I Had Sex The 17th Of October, He Pulled Out.

I had sex the 17th of october, he pulled out. Then had sex the 25th, he pulled out again and I don't think he came at all in me but I have missed my period on the 20th which was my last period I got the month before. I took plan b 8 hours after it happened. This is the second day, I can finally eat again, I'm now a little dizzy and Ive been having a pink discharge and wondering if this is because I delayed my period? ( Ive had cramps before I had sex the second time, still do) should I worry?