Confused ...

So Idk what’s going on... I had my period on December 29th and ended the first or second of January. That was January’s period. Sometimes my periods ran like that. Well I had sex a week and half before my next period. Twice and he got off in me both times. I ended up started my “period” on the 26th but it was only 3 days and it was a light light bleed. It didn’t go into February. So it can’t be that months period. It didnt last as long it was suppose to. I’ve taken 2 tests both negative. I have the old <a href="https://play.google.com/store/apps/details?id=com.glow.android.nurture">pregnancy tracker</a> from my sisters pregnancy and I edited for my last period date and it said I would be 7 weeks (if iwas and if December 29th was my last start date ) I was just doing it to see if i was testing early. I haven’t retested yet but Idk . I just have this huge feeling the tests were wrong. I’ve been feeling very nauseated lately not all the time just random moments some smells bother me. I’m way more tired then I use to be. I’m getting really bad headaches and I have a strange cramp feeling all the time. (This is gonna sound weird) but I’m pooping WAY WAY more then I usually do. Like 3 times a day. My sister was like that and I know every girl is different but Idk. I feel like the tests are wrong but Idk at the same time I’ve wanted this for so long that I think I’m imagining it