The Phases of the Menstrual Cycle
During a woman’s monthly menstrual cycle, an egg develops and is released from the ovaries. Also during this time, the lining of the uterus thickens in preparation for pregnancy. If pregnancy doesn’t occur, the uterine wall breaks down and sheds out of the body as part of a woman’s monthly period.
And then the cycle starts again.
What many of us don’t know is that there are several phases of the menstrual cycle. This blog will guide you through it from start to finish.
The Menstrual Cycle
Stage 1. The Menstrual Phase
The menstrual phase begins when your egg from the previous cycle is not fertilised. Your levels of estrogen and progesterone drop, causing the lining of your uterus to break down and shed through the vagina. This is the bleeding you experience on a period. Other symptoms during this stage also include:
- Mood swings
- Low back pain
- Tender breasts
For most women, the menstrual phase lasts from three to seven days.
Stage 2. The Follicular Phase
The follicular phase overlaps with your menstrual phase as it also begins on the first day of your period. During this stage, your hypothalamus will signal your pituitary gland to release FSH (follicle-stimulating hormones). These hormones cause your ovaries to grow up to 20 small follicles. Each of these follicles contain an egg and only the healthiest in this batch will eventually mature. In some rare cases, a woman can produce up to two mature eggs. The body absorbs the rest of the follicles.
As your egg matures, your estrogen levels will also increase — stimulating your uterus to build up its lining so the soon to be fertilised egg will have an environment to grow. For healthy women, the average follicular phase is 16 days. However, it can last up to 27 days.
Stage 3. The Ovulation Phase
The follicular phase causes a rise in estrogen levels in the body. Rising estrogen levels then stimulate the pituitary gland to release another type of hormone called the luteinising hormone or LH. This chemical is responsible for ovulation which is the third phase of the menstrual cycle.
During ovulation, your ovary releases a mature egg which travels to the uterus via your fallopian tubes. The mature egg stays here until a sperm fertilises it. You will only get pregnant during the ovulation phase.
How do you know if you are ovulating? Keep an eye on these common symptoms:
- A thick egg white-like discharge from your vagina
- A slight rise in your body temperature
If you have a regular menstrual cycle, ovulation usually happens in the middle of your cycle. This stage will only last about 24 hours. If no sperm fertilises the egg during this period, the egg will die.
Stage 4. The Luteal Phase
Your mature follicle changes into a different structure called corpus luteum after it releases its egg. This structure floods your body with high levels of progesterone and estrogen to keep your uterine linings thick and ready in the event of successful fertilisation.
If you get pregnant, your body will produce another hormone called human chorionic gonadotropin or hCG. This hormone is responsible for maintaining the corpus luteum which in turn keeps your uterine wall thick. Pregnancy test kits in the market are specifically designed to detect the presence of hCG.
However, if you don’t get pregnant, the corpus luteum shrinks and is reabsorbed into the body. As a result, your progesterone and estrogen levels drop causing the linings in your uterus to shed. The menstrual phase then starts again.
For healthy women, the average luteal phase lasts about 14 days. During this phase, you may experience symptoms of PMS which includes:
- Mood changes
- Weight gain
- Inability to sleep
- Swelling or tenderness in the breasts
Regulate your menstrual cycle using contraceptive pills
Many women choose to delay their menstrual cycle for health, travel, and personal reasons. One of the best ways to regulate your period is by using contraceptive pills. There are two common types of contraceptive pills in the market:
Combined Pills - a type of contraceptive pill that contains synthetic versions of progesterone and estrogen. This helps regulate your menstrual cycle by stopping the ovulation phase.
Mini Pills - these contraceptive pills contain progesterone and are often the recommended choice for women who are overweight and have high blood pressure. Mini pills work in the same way as combined pills.
Contraceptive pills come in packs. For 21-day packs, you’ll get your period during the fourth week. For 28-day packs, you’ll get your period after taking your pills for four weeks. Lastly, there’s the 91-day pack where you get your period every 12 weeks.
The common side effects of contraceptive pills include:
- Mood changes
- Changes in your appetite
- Weight fluctuations
- Unwanted hair growth
- Increased blood pressure