Pregnant?

I had sex for the first time..the first round was with a condom second third and fourth with out he said he didn't cum in me.. can you feel when someone cums inside you?? The last time he came on my back... ever since then I've been paranoid I've been on birth control I think it was my 6th or 7th day I took a plan B after and I got my period... can I still be pregnant?