When Is A Woman Most Fertile?

hi. i have two questions to ask. one, i have been having unprotected sex with my husband everytime my periods end for tens days and ive been doing so for the last one or so year. if my most fertile days are just right after my periods does that mean am not fertile? two... am taking ova care pills and i just wanted to know since i have to wait for atleast three weeks to know if am pregnant or not, what if i get pregnant and i continue taking the pills without knowing can if affect my baby. thanks you in advance