What Happens After Ovulation

It is only possible to get pregnant for a short period of time after ovulation. After ovulation—when the egg is released from the follicle—there is a period of 12 to 48 hours when the egg is available to be fertilized by a mature sperm. Sperm can last for up to 5 days inside a woman’s body, sustained by the cervical mucus. Often, just after ovulation sperm that is waiting in the fallopian tubes will fertilize the egg when it is released. Healthy, active sperm takes around 6 hours after ejaculation to swim through the cervix and the womb into the fallopian tube to meet a waiting egg. To that end, it is still possible to get pregnant 1 to 2 days after ovulation.

In any one menstrual cycle there will be just one fertile period. Follicle stimulating hormone (FSH) stimulates the growth of ovarian follicles in the ovary before the release of an egg at ovulation.  Because ovulation is triggered by a particular combination of hormones that rise and fall over the normal menstrual cycle, eggs can only be released from the ovaries during the 24-hour period when the ovulation-promoting hormones are at their peak.

A pregnancy with fraternal twins results from 2 eggs being released from 2 different follicles within the same 24-hour period. Twins occur once in every 76 births.

Advances in ultrasound technology have led to research into vanishing twin syndrome. It is now thought that it occurs in up to 30% of multifetal pregnancies. Vanishing twin syndrome involves the very early fertilization of more than one egg, but the second embryo will not survive for more than a few weeks after ovulation. If the embryo does not survive, it is reabsorbed by the body.

After ovulation, hormone levels decline and you must go through a feedback cycle which triggers menstruation before you ovulate again.

For the 8 days or so after ovulation, the same events occur in your body whether the egg has been fertilized or not. The follicle that released the egg grows larger and turns into a gland-like structure called the ‘corpus luteum.’ After this, it starts to produce the hormone progesterone. Progesterone causes the lining of the womb to thicken and become covered with mucus that is produced by glands within the endometrium.

If you are not pregnant within 48 hours after ovulation the egg moves along the fallopian tubes, disintegrates, and is absorbed back into the body.

The corpus luteum survives and continues to produce progesterone for 12 to 14 days. After this it dies, unless it receives the hCG hormone released from an embryo. The level of progesterone in the body drops and the endometrium responds by shutting off its arteries, preventing blood from flowing to and from the surface of the uterine lining. The blood that is already in the lining then pools in the womb and the mucus-covered uterine lining. Deprived of oxygen it dies back, with the blood and lining seep into the vagina. Menstruation occurs and the cycle begins again. After ovulation and until menstruation, your basal body temperature remains about 32 degrees Fahrenheit or higher. Your cervical mucus becomes less slippery, stickier, and creamier in consistency.

The moment that one of the millions of sperm enters the outer surface of the egg, the egg’s coating changes so no other sperm can enter. The sperm and egg combine and form a zygote.  The zygote takes around 5 days to travel down the fallopian tube. The cells divide and eventually form a blastocyst. Around 8 to 10 days after fertilization, the blastocyst implants into the wall of the womb.

Before implantation, there’s not a lot of change going on in your body, which behaves just as it would if you weren’t pregnant. But after ovulation and implantation the fun begins. Sometimes there is slight spotting or bleeding just after implantation and some women mistake it for a period. But when the blastocyst attaches to the endometrium and becomes an embryo, various hormones are released. They thicken the endometrium and seal the cervix with a plug of mucus.

The embryo and placenta develop separately. After implantation, the placenta produces the hormone human chorionic gonadotropin (hCG). Within a few days, the level of hCG is able to be detected in urine through a pregnancy test.