while there are certain times during a woman's monthly cycle where she may be less likely to get pregnant this is a very unreliable method for preventing pregnancy. first of all a woman would need to know when she's ovulating and most women cannot reliably tell. and even if she can tell there is still a chance she could get pregnant even if she avoids sex for several days following ovulation. i would not recommend this approach if you're trying to prevent pregnancy. it has a high rate of failure. also of course unprotected intercourse always runs the risk of transmitting stds such as herpes gonorrhea chlamydia and even hiv.
is it ever safe to have unprotected sex? i've heard women cannot get pregnant right before their period. is this true?