 [ Symptoms ] can you get a yeast infection from taking doxycycline [ Disease ] hi so she should have had her period between the 3rd and 5th and you both had unprotected sex on the 4th so what makes you think she pregnant day 1 of her cycle period day 14 or about then is her ovulation day and all being well around day 28 her new period starts ok if you had sex on day 13 then she could have gotten pregnant but not around the day of her period unless she has a very odd system could be that she has just skipped her period it can happen hope this helps you both good luck ps i would carry more condoms or get her on some kind of bc if all is well but not depo shot the side effects a can be very bad