I'm not sure if I'm pregnant or not

Sooooo I'm not sure if I'm pregnant. My last period was April 14-18th and it's usually the normal 4 day heavy bleeding for me. I was supposed to have a period the week of May 12th. That Monday, I was barely spotting/ it was mainly discharge. I haven't had a sign of a period since. My boyfriend and I have unprotected sex and while I was on the pill, I wasn't taking it like I should have been. The week of my more or less missed period I took two pregnancy tests and they both came back negative. Since then, I've been tired and hungry often and have to pee a lot. And tonight, It really started to bother me when I went to lay on my stomach in bed and I felt nauseous and my stomach just feels weird. I'm not sure how to describe it other than it feels really weird when I lay on it. Pleaseeee help 😱