girls, my periods have been regular for the past 4 months but before that they were very irregular (like 4-5 months between) but now my period is almost a month late and I have had sex since my last period (he definitely pulled out). I am supposed to start the contraceptive pill today and I don't know if I should because then I won't know if I'm pregnant?!?! is it just irregular and I can go on the pill now or should I wait to get my period???