Terrified.

So I had a pregnancy scare about 2 months ago and I was 3 weeks late. 2 negative test. And I got AF. I've had a period twice since then but here lately I've been nauseous everytime I eat and I gag at stupid things that should really make me sick. Like a guy friend shoved a tampon up his nose and I about threw up. And I have dirrareh about once a day ish but I do poop everything.  My periods were normal just like any other. But I don't understand why I keep getting nauseous but I don't  wanna say anything cause what if I was pregnant. I'm a senior in HighSchool I can't be pregnant I have too much going for me. I'm just nervous and don't know what to do cause if I'm not pregnant then something has to be wrong.