Everything You Need to Know About Menstrual Cycles and Ovulation

Menstrual Cycles: The Basics

Ovulation is a key part of your cycle, but it's essential to understand what a menstrual cycle involves. It starts on the first day of menstrual bleeding and ends just before the next period begins. The duration of cycles typically ranges from 24 to 38 days, with only 10 to 15% of women having a 28-day cycle exactly. Around 20% of women experience irregular cycles. The cycle duration can be particularly variable at the beginning of menstruation and before menopause. It's important to understand that an irregular cycle is one with a variance of more than 7 days.

Hormonal Regulation of the Menstrual Cycle

The menstrual cycle is controlled by a complex interaction of several hormones:

• Luteinizing Hormone (LH)
• Follicle-Stimulating Hormone (FSH)
• Estrogens
• Progesterone

These hormones, produced by the pituitary gland and the ovaries, regulate the development of follicles, ovulation, and the preparation of the uterus for potential fertilization.

Phases of the Menstrual Cycle

Follicular Phase

This phase starts with menstrual bleeding. Estrogen and progesterone levels are low, causing the shedding of the endometrium (the uterine lining). FSH stimulates the development of follicles, with one becoming dominant and producing estrogen. This phase typically lasts 13 to 14 days but can be much longer. The follicular phase is responsible for menstrual cycle irregularity since ovulation can occur earlier in some cycles and later in others. In contrast, the luteal phase duration, which we will discuss later, varies little; thus, it is the follicular phase that frequently causes irregular cycles.

Ovulatory Phase

This phase is marked by a surge in LH, triggering the release of the egg (ovulation). It lasts about 16 to 32 hours and ends with the egg being released, ready to be fertilized for about 12 hours. Ovulation generally occurs between 16 and 32 hours after the LH peak. To confirm ovulation reliably, the temperature method (or Symptothermal method) is the most accurate. This part of the cycle is crucial, whether trying to conceive or not, as it influences the luteal phase and premenstrual syndrome experienced during the second half of the cycle.

Luteal Phase

This phase begins after ovulation and lasts about 14 days (up to 17 days). The ruptured follicle becomes the corpus luteum, producing progesterone to thicken the endometrium. If the egg is not fertilized, the corpus luteum degenerates, leading to a drop in hormones and the onset of menstruation.

Menstruation corresponds to the monthly shedding of the endometrium, the inner lining of the uterus, accompanied by bleeding. Menstruation starts at puberty (menarche) and stops at menopause, defined as one year after the last menstrual period. Outside of pregnancy and menopause, menstruation usually occurs monthly. Menstrual bleeding typically lasts between 4 and 8 days, with blood loss ranging from 6 to 70 ml per cycle. A sanitary pad or tampon can hold up to 30 ml of blood. Unlike blood from wounds, menstrual blood does not clot, except in cases of heavy bleeding.

Ovulation Symptoms

Ovulation is the process by which a mature egg is released from one of the ovaries. Once released, the egg travels down the fallopian tube, where it can be fertilized by sperm if they are present. If the egg is not fertilized, it disintegrates and is shed from the body during menstruation.

Ovulation Pain

Some women experience pain in their lower abdomen mid-cycle, which can vary in intensity. This pain occurs on the side of the ovary that released the egg and can last from a few hours to a whole day. It is caused by the release of luteinizing hormone (LH), which triggers the release of the egg from the follicle and causes muscle contractions in and around the ovary.

Ovulation pain is usually less intense than menstrual pain but can cause:

• Twinges: In the lower abdomen, often on one side.
• Cramps: Sometimes intense.
• Bloating: Symptomatic of ovulation.

These pains usually last for a day or two. If the pain persists or occurs at another time in the cycle, consult your gynecologist to rule out any pathological causes (such as polycystic ovary syndrome, endometriosis, ovarian torsion, etc.).

Ovulation and Spotting

Ovulation spotting is a light blood loss that occurs when an egg is released from one of your ovaries, typically around the middle of your cycle, 11 to 16 days before your next period. This bleeding usually lasts 1 to 2 days.

Ovulation bleeding occurs due to a sudden hormonal change: the drop in estrogen after its pre-ovulatory peak, replaced by a rapid rise in progesterone. This variation can cause a slight shedding of the uterine lining, resulting in light bleeding. Another cause could be the rupture of blood vessels during the release of the egg.

Differentiating Ovulation Spotting from Other Bleeding

• Ovulation Bleeding vs. Menstruation: Ovulation spotting is lighter, clearer, shorter, and occurs about 14 days before your period.
• Ovulation Bleeding vs. Implantation Bleeding: Implantation bleeding, occurring 6 to 12 days after conception, is an early sign of pregnancy. It happens later in the cycle compared to ovulation spotting.

Ovulation and Cervical Mucus

Cervical mucus is produced by the cervix under the influence of menstrual cycle hormones. Often confused with vaginal discharge, cervical mucus plays a crucial role in female fertility.

Role of Cervical Mucus

Cervical mucus has three main functions:

• Filters and selects the healthiest sperm.
• Protects sperm from vaginal acidity.
• Helps sperm reach the egg.

Cervical Mucus Changes Throughout the Cycle

Cervical mucus changes in consistency, color, and amount throughout the menstrual cycle:

• After Menstruation: Hardly visible or sticky, sometimes dry.
• Follicular Phase: Increasingly creamy and milky.
• Ovulation: Clear, slippery, and stretchy, resembling raw egg white.
• After Ovulation: Becomes thick and sticky again.

To observe your cervical mucus:

• Collect it with toilet paper or directly from the cervix.
• Assess its consistency and stretchiness.
• Note your observations in a journal or a dedicated app.

dry or absent / creamy / wet but not stretchy / egg white or watery

Ovulation Without Cervical Mucus