Plan B

I had unprotected sex on Dec. 23 and bf didn’t pull out, but I took a plan b maybe 2 hrs after. I had what seemed like a period on Dec. 31. Jan. 12 tested and was negative.On Jan. 16 I felt terrible (nausea, light headed, possible side effects of plan b?) Feb. 1 tested again and still negative. Haven’t got my period since Dec. 31, could I be pregnant or my cycle is messed up?

***UPDATE***

I retested today which is 2/10 (morning urine) and both looks negative to me; however, AF still hasn’t made her appearance. Im confused??