I took plan b 3 weeks ago and I still feel nauseous and I get little cramps. I took 3 neg tests 3 weeks after unprotected sex. I’m ovulating I think??

Pregnancy negative. If your results already negative you are not pregnant. But you might be unbalanced hormonally so follow up with hormonal blood test and Hcg levels if <5mIU neg for pregnancy above >25mIU positive 6-24 retest.