can i get pregnant if i had unprotected sex 2 days before my period comes??

What do the experts say?

Can you get pregnant if you have unprotected sex a few days before your period, during your period, or in the days immediately after your period ended? These questions are of interest to nearly every woman who had or is planning to have sexual intercourse without protection and who doesn't want to get pregnant. 

The answer is surprisingly different than what you may have learned in high school sex ed, and goes contrary to popular wisdom as well. Wait, what? Doesn't a sperm cell have to fertilize an egg cell for a woman to get pregnant? And doesn't ovulation, the process during which eggs are released, take place neatly in the middle of the menstrual cycle, between two periods? While the answer to the first question is still "yes", answering the second question is more complex. Our bodies, it turns out, don't always follow the tidy scientific models we come up with. 

The fertile window

All the way back during the first world war, a doctor who was — for some reason — looking into pregnancies that occurred after women had one-night stands with soldiers on leave, found that women got pregnant after having sex during wildly varying times in their menstrual cycles. That is, the earliest known cycle day on which a woman in this study conceived was day two, while day 30 was the latest time during which a woman got pregnant. Much more recent research noted that there are no more recent studies detailing such a wide range. 

More research has indeed been conducted since then, however, and the findings may surprise you:

• Women have a 10 percent chance of being within their "fertile windows" (meaning they can get pregnant) every single day between cycle days six and 21. 
• Up to five percent of women occasionally ovulate in the fifth week of their menstrual cycles. 
• Only a third of woman have ovulations that neatly fall into established clinical guidelines, meaning they ovulate between days 10 and 17. 

It is true that you're highly unlikely to conceive on certain cycle days — research found that any given woman of reproductive age has less than a one percent chance of getting pregnant two days after menstruation started, while half of all woman will be fertile on cycle days 12 and 13. Highly unlikely isn't the same as "not possible" though. Contrary to popular belief, some women do indeed get pregnant during this time. 

Even women who reported that their menstrual cycles were very regular had, a study indicated, a possibility of being fertile within the fifth week of their cycles, even in the days before their next menstruation was expected or on the day itself. Statistically, the chance of this happening to you is somewhere in the range of one to five percent. This is probably a lot higher than most women think. 

The "rules" about fertile windows that you've come to know are not incorrect, as such, as they broadly correspond to your statistical likelihood of ovulation. It's just that woman can and do fall outside of these guidelines, and if you don't want to get pregnant, you can't count on not being one of them. 

What now?

The scientific method has brought us the probably unwelcome realization that you can, indeed, get pregnant at basically any time at all. What does this mean? It sends the message that any woman who is very sure that she wants to avoid pregnancy should turn to reliable birth control methods such as condoms, the contraceptive pill, intrauterine devices, or any of the other methods now available. Most medical birth control methods are around 99 percent effective at preventing pregnancy when used correctly. 

Research has also shown that looking at your cervical mucus — you're looking for a "stretchy", transparent texture that looks an awful lot like raw egg whites — is quite reliable at telling you when you are close to ovulation. This method will help couples who are trying to conceive out, but it isn't something you should turn to if you are looking to prevent pregnancy. You can also use ovulation tests to figure out when you are definitely fertile, but because sperm cells can live inside the female reproductive tract for around five days, the days on which intercourse can lead to pregnancy are a bit broader than those tests would suggest. 

Women who have just realized that it is theoretically possible to get pregnant during almost any time within their menstrual cycles and who recently had unprotected sex can consider the morning-after pill or ParaGard IUD as emergency contraception. 

Anyone who thinks they may be pregnant can, meanwhile, take a pregnancy test — because it is hard to determine the right time to take it if you conceived during an unusual time, seeing a doctor is a wise step.