I was sexually active on monday i got my period wednesday morning before buying a pill but i still took the pill. will it work the same way?

Not exactly,: If you are referring to the Plan B pill, but if you had already started your period then you weren't pregnant anyway. You should use reliable birth control to prevent pregnancy. Plan B is intended for emergency use, but should not be used recurrently as a form of birth control. Condoms are not effective birth control but are the best method for preventing sexually transmitted infections