If you had sex the first day of your period and he came its very doubtful that you are pregnant because your uterus lining is shedding and is basically cleaning its self. as for the other times if you had sex after your period and he came in you and you guys didn't use a condom you can actually test 6-12 days after. Good luck!
U can do a home test 19days after sex or a doctor can do 1 after abwt 11days
hope this helps u babe