My first time was in May. My boyfriend used condom but just to be sure i took an i-pill(which is similar to Morning after pill,plan b). The next day i got my period which was almost 4-5 days long. am i pregnant?

i was supposed to get my period in June but i didn't, i.e. i missed a period and again in June 28th (which is after my due date for period) i had unprotected sex but my boyfriend didn't ejaculate inside of me. and i took i-pill within 1 hour. now it july 3rd and i haven't got my period. i'm experiencing lower back pain and my breasts are painful too. am i pregnant or are these symptoms of something else. i'm really worried please reply soon.