HELP ME PLZ!! I'M REALLY WORRIED!!!

So I've been on the pill for 6 months now and I feel nauseous now for about 2weeks. I've also been booted for about a month and a half now. But I have no weight gain. I have never missed a pill and I take it at the same time everyday. My boyfriend and I have unprotected sex since I started the birth control. He has not come inside me. But I'm just a little worried. Could this be a delayed side effect from the pill?!