Although it is possible to get pregnant in the days leading up to your period, it isn’t likely. You can only get pregnant during a narrow window of five to six days a month. When these fertile days actually occur depends on when you ovulate, or release an egg from your ovary.

However, their fertile window began a few days before ovulation because sperm can survive for up to 5 days inside the female body. So, even if a woman does not have sex on day 14 or 15, it is still possible to become pregnant if they had unprotected sex on days 9 to 13.

Early ovulation has sometimes been thought to signal a less fertile cycle. For example, some authorities state that a cycle is seldom fertile when ovulation occurs before day 13 of the menstrual cycle. We found no evidence of this. Indeed, the earliest ovulation in our study (cycle day 8) produced a healthy infant.

Even though you don’t have your period, changes are still happening in your reproductive system. Days 13/14 Ovulation happens around this time. (Some women have cramps, but you likely won’t feel a thing when you ovulate.) Days 15/16 Hormone levels rise.

There is even more chance of a woman becoming pregnant if she has sex during the two days leading up to or on the day of ovulation. Women who have a period every 28 days will ovulate around day 14 and their best chance of conceiving is between days 11 and 14.

How can I tell when I’m ovulating?

• the length of your menstrual cycle – ovulation usually occurs around 10 to 16 days before your period starts, so you may be able to work out when you’re likely to ovulate if you have a regular cycle.
• your cervical mucus – you may notice wetter, clearer and more slippery mucus around the time of ovulation.

Your menstrual cycle and period are controlled by hormones like estrogen and progesterone. Here’s how it all goes down: You have 2 ovaries, and each one holds a bunch of eggs. The eggs are super tiny — too small to see with the naked eye.

Ovulation happens about 14 days before your period starts.

• If your average menstrual cycle is 28 days, you ovulate around day 14, and your most fertile days are days 12, 13 and 14.
• If your average menstrual cycle is 35 days ovulation happens around day 21 and your most fertile days are days 19,20 and 21.

The most common cause of irregular or heavy bleeding is irregular ovulation. If there is no ovulation your period may be late and when it comes it may last a long time or be unusually heavy. Irregular ovulation is more common if you are underweight or very overweight.

Sperm can fertilize an egg for 3 days. So if a girl has sex on the last day of her period and ovulates in the next few days, the sperm may still fertilize the egg.

You’re most fertile at the time of ovulation (when an egg is released from your ovaries), which usually occurs 12 to 14 days before your next period starts. This is the time of the month when you’re most likely to get pregnant. It’s unlikely that you’ll get pregnant just after your period, although it can happen.

Can you get pregnant on your period? A person can get pregnant during their period, but it is unlikely. A person is most likely to become pregnant in the middle of their menstrual cycle, which is when the ovary releases an egg in a process called ovulation.