Could i be pregnant even do i took plan b and did bleed 5days after taking it?

i'm really worried now,it's already july 8 i haven't got my period and my last period was on the 1st week of june.It was 5days after taking plan b,it lasted 4 days only.It was my 1st time of having sex with my bf last may 23.He did not ejaculate in me cause i had to stopped him of what his doing for it was too painful.He assures me that i will not get pregnant cause he didn't ejaculate.I read that once his penis get in to mine theres a chance of getting pregnant .Because of the fear of getting pregnant right after i came home,i did research and found out about plan b.On the 25th of May i took Nordette a ,after 5 days i got my period as i was saying ealier.It was a relief that plan b did work.But now it bothers me so much that i haven't get my next period after that bleeding(1st week of june).I already tried pregnancy test twice both are negative.First was on june 28 since i have read some blogs that you can take PT 21 days after having sex,we had sex on may 23 so it was over 21 days after.I was so happy of the result negative.The month of july came and i didn't get my period so i tried PT again last july 2 and it's also negative.Now it's july 8 and i haven't get my period.Though in my case the chances are lesser but why i haven't get my period yet???;-(