Heather Corinna replies:
I was given an assignment in health class, asking to get this question answered on your website. I know this is a very common question among teens and thought you could help me and my classmates out. I will be bringing your response to this question into class to discuss with other peers. The question is...Can I get pregnant the first time we do it without protection? I hope to hear back from you very soon considering this is an assignment I need to report back to my health class with this information as soon as possible.
Ask my Mom: she sure did, and here I sit, the proverbial proof in the pudding. :)
Yes, you can. First-time intercourse doesn't change anything about your fertility. In other words, if a woman has begun menstruating, that's because she first began ovulating. In other words, the first time a woman ovulates -- when her ovaries release the first egg -- around two weeks later she'll have her first period. First ovulation and first menstruation tend to occur well before most women choose to become sexually active.
And once that happens, a woman can become pregnant. She doesn't need to have intercourse any given number of times for pregnancy to occur. High pregnancy risks are present from unprotected intercourse the first time, the third time, or the fifty-seventh time. Within one month of having intercourse without reliable birth control, around 25% of women will become pregnant, and within a year, around 85% will.
It should also be mentioned that since no method of birth control (save not having sex) is 100% effective, while reliable birth control can reduce that risk pretty greatly, it's also possible someone could become pregnant the first time they have intercourse even WITH protection, especially if a given method isn't used properly, or used for all direct genital contact.
Here's a few links for you and your classmates to give you more information on how the fertility cycle works, how pregnancy happens, birth control effectiveness rates, and when pregnancy risks are posed:
P.S. If you have a health teacher sending you to resources like this, and who is supporting you in researching answers to sexuality questions, you are one lucky student! Bring him or her an apple tomorrow, eh?