pregnant?

I have sex with my boyfriend regularly and I'm on the pill and we use a condom. I have to admit that I was a little forgetful about my pill a few times this month but got right back on track quickly. I'm supposed to get my period soon(like 4days) but this whole week I was nauseous and bloated and I've never PMSd before. Idk if I'm just stressed out about nothing or if I should be nervous since it's not even when I'm supposed to get my period. Am I just stressed out or should I keep an eye on it?