Placebo pills & irregular periods... help!

Hey ladies! So my period ended last week on Thursday while I was on the white birth control pill (microgestin) and yesterday I started the placebo (brown pills). I have terrible cramps & did have sex right after my period (last Saturday). Will my period come again this week even though I just had it? Or should I only take 3-4 brown pills and start the white ones again? I was taking birth control while having sex. I want to be safe, but am not sure why my period has been so back to back... I've been on it almost 2 years. Does it need to regulate again? Thanks so much xx