PLEASE, HELP ME?!

PLEASE ANSWER THE QUESTIONS BELOW:

   so on March 4th (6 days after my period for February ended), my boyfriend and I had PROTECTED sex. He had a condom on the entire time. While inside of me, I thought that he came, because when I was finishing him the condom seemed to be able to slide (move) a lot more than normal (I finish him off by giving him a HJ). He never cums inside of the condom while inside of me, EVER. He swore up and down that he never did, but to be on the safe side I had him go buy Plan B. I took the pill within an hour or two of the possible incident. (I have taken Plan B before, three times, and I have never experienced this before. My period usually started within a week of taking it). 

   However, I was scheduled to start my period on March 23, but it never came. On the 26th, I started to lightly bleed, almost like spotting. It was very faint blood, almost pink, with a little bit of blood every now and then. It lasted on and off for 4 days. I still had my normal PMS symptoms: cramps, bloating, swollen breasts, and nausea. WAS THAT MY PERIOD? If not, I'm basically 3 weeks late. 

I still feel my PMS symptoms on and off now, but I feel little fluttering feelings every now and then (I've felt these before), what's causing that? 

•was that my period?

•can Plan B make you miss a period?

•COULD I BE PREGNANT?! 

•is this normal?

•••HELP•••