As for when to check your blood pressure, the most important thing is to do it consistently the same time of the day (ask the doctor which time he prefers and also what time in relation to taking your medication). The following article has a lot of good information for someone just starting to monitor their blood pressure:
Preeclampsia is elevated blood pressure and the leakage of protein into the urine by the kidneys. Preeclampsia can be dangerous to both mother and baby. High blood pressure during pregnancy may lead to decreased blood flow to the placenta, placental abruption, premature delivery, or future cardiovascular disease. After the baby is born, high blood pressure during pregnancy usually returns to normal levels.
4. Find an exercise that works for you (and do it). Moving more can help reverse high blood pressure. One meta-analysis of 65 studies found regular exercise provides both an acute and longer-term reduction in blood pressure. Whether you’re an exercise novice or a conditioned athlete, these four strategies can help you create an effective workout plan to optimize health. 

Postural hypotension is considered to be a failure of a person's cardiovascular system or nervous system to react appropriately to sudden changes. Usually, when a person stands up, some of their blood pools in their lower extremities. If this remains uncorrected, it would cause the person's blood pressure to fall or decrease. A person's body usually compensates by sending messages to their heart to beat faster and to their blood vessels to constrict, offsetting the drop in blood pressure. If this does not happen, or does not happen quickly enough, postural hypotension is the result.
You are considered to have hypertension if your systolic blood pressure measurements are between 130 and 139 or your diastolic measurement falls between 80 and 89. At this level of blood pressure you may not have any symptoms. When blood pressure reaches 180/120 or higher, a serious condition known as a malignant hypertension or hypertension crisis may occur. This can lead to stroke, kidney damage, heart attacks, or loss of consciousness. If you measure your blood pressure and it is this high, rest a few minutes and measure again. If it remains high, call 911.
Health care providers measure blood pressure with a sphygmomanometer (sfig-mo-muh-NAH-muh-ter), which has a cuff that's wrapped around the upper arm and pumped up to create pressure. When the cuff is inflated, it squeezes a large artery in the arm, stopping the blood flow for a moment. Blood pressure is measured as air is gradually let out of the cuff, which allows blood to flow through the artery again.
Keeping track of your blood pressure is important. Your doctor can help you learn how to check your blood pressure at home. Each time you check your own blood pressure, record your numbers and the date. Send or take the log of your blood pressure readings with you for appointments with your doctor. Return to Screening for reminders on how to prepare for blood pressure testing. 

Hypertension may not produce any symptoms, even if you have had it for years. That's why it is sometimes referred to as a "silent killer." It's estimated that 1 out of every 5 people with high blood pressure aren't aware that they have this major risk factor for strokes and heart attacks. If not properly treated, high blood pressure can damage the heart and circulation, lungs, brain, and kidneys without causing noticeable symptoms. Symptoms of high blood pressure may be present in those who have an extremely high blood pressure. Symptoms of extremely high blood pressure include the following:
A reduction from 8% to 6% of cardiovascular events is known as an absolute risk reduction of 2%. This may seem small, but the translation is not small when applied to real world people. This can be understood more easily as something called “number needed to treat” which is calculated by 1 divided by the absolute risk reduction. In this case, an absolute risk reduction of 2% translates to a “number needed to treat” of 50 (1 divided by 0.02 = 50). This means that 50 people need to have a BP down to < 120/80 in order for 1 cardiovascular event to be prevented. In the context of many other things we do in our life (medical treatment or not), this is really good!
About This Image: Person receiving a blood pressure test. Medical research shows that as we age blood pressure rises slightly to accommodate an increased demand of oxygen and nutrients. It is completely natural for the first number (systolic) to be 100 plus our age. A recent study by a group of UCLA researchers came very close to corroborating Dr. Piette's guide for blood pressure of 100 plus your age for men, subtracting 10 for women, and this is after this rule had been in use for five or more decades. Are we now being taught that Dr. Piette's guide for blood pressure is wrong merely for drug company profit?
James, Paul A.; Oparil, Suzanne; Carter, Barry L.; Cushman, William C.; Dennison-Himmelfarb, Cheryl; Handler, Joel; Lackland, Daniel T.; Lefevre, Michael L.; MacKenzie, Thomas D.; Ogedegbe, Olugbenga; Smith, Sidney C.; Svetkey, Laura P.; Taler, Sandra J.; Townsend, Raymond R.; Wright, Jackson T.; Narva, Andrew S.; Ortiz, Eduardo (18 December 2013). "2014 Evidence-Based Guideline for the Management of High Blood Pressure in Adults". JAMA. 311 (5): 507–20. doi:10.1001/jama.2013.284427. PMID 24352797.

Some high blood pressure medications initially cause drowsiness, dizziness, and lightheadedness. Some even cause fainting on the first dose. The body usually adjusts to the effects of these medications and the side effects disappear. Consuming alcohol during the early phase of antihypertensive treatment could be risky because alcohol can also cause dizziness, drowsiness, and lightheadedness.
Blood pressure refers to the force exerted by circulating blood on the walls of blood vessels and constitutes one of the principal vital signs. The pressure of the circulating blood decreases as blood moves through arteries, arterioles, capillaries, and veins; the term blood pressure generally refers to arterial pressure, i.e., the pressure in the larger arteries, arteries being the blood vessels which take blood away from the heart.
Weakened heart muscle can cause the heart to fail and reduce the amount of blood it pumps. One common cause of weakened heart muscle is the death of a large portion of the heart's muscle due to a single, large heart attack or repeated smaller heart attacks. Other examples of conditions that can weaken the ability of the heart to pump blood include medications toxic to the heart, infections of the muscle of the heart by viruses (myocarditis), and diseases of the heart's valves such as aortic stenosis that reduce the flow of blood from the heart and into the arteries.
Blood pressure is the force exerted by circulating blood on the walls of blood vessels. It constitutes one of the critically important signs of life or vital signs, which include heart rate, breathing, and temperature. Blood pressure is generated by the heart pumping blood into the arteries modified by the response of the arteries to the flow of blood.
The primary symptoms of malignant hypertension is a blood pressure of 180/120 or higher and signs of organ damage. Other symptoms of malignant hypertension include bleeding and swelling of blood vessels in the retina, anxiety, nosebleeds, severe headache, and shortness of breath. Malignant hypertension may cause brain swelling, but this symptom is very rare.

Physical examination may include listening to the heart and lungs, feeling for pulse in the wrist and ankles, and feeling and listening to the abdomen looking for signs of an enlarged aorta. The examiner may also listen in the neck for carotid bruits (sounds made by a narrowed artery in the neck) and in the abdomen for bruits made by an abdominal aortic aneurysm.

Even occasional dizziness or lightheadedness may be a relatively minor problem — the result of mild dehydration from too much time in the sun or a hot tub, for example. Still, it's important to see your doctor if you have signs or symptoms of hypotension because they can point to more-serious problems. It can be helpful to keep a record of your symptoms, when they occur and what you're doing at the time.

Dietary changes can help control blood pressure. One diet designed to promote lower blood pressure is known as the DASH diet. This stands for Dietary Approaches to Stop Hypertension. The DASH diet recommends eating more vegetables, fruits, whole grains, low-fat dairy products, poultry, nuts, and fish. Red meat, saturated fats, and sweets should be avoided. The DASH diet can lower blood pressure within 2 weeks. It can also help to reduce your intake of sodium. The following is the DASH diet suggested daily intake:
How the heart pumps blood into the arteries with enough force to push blood to the far reaches of each organ from the top of the head to the bottom of the feet. Blood pressure can be defined as the pressure of blood on the walls of the arteries as it circulates through the body. Blood pressure is highest as its leaves the heart through the aorta and gradually decreases as it enters smaller and smaller blood vessels (arteries, arterioles, and capillaries). Blood returns in the veins leading to the heart, aided by gravity and muscle contraction.

^ Saiz, Luis Carlos; Gorricho, Javier; Garjón, Javier; Celaya, Mª Concepción; Muruzábal, Lourdes; Malón, Mª del Mar; Montoya, Rodolfo; López, Antonio (2017-10-11). "Blood pressure targets for the treatment of people with hypertension and cardiovascular disease". Cochrane Database of Systematic Reviews. 10: CD010315. doi:10.1002/14651858.cd010315.pub2. PMID 29020435.