Can i be having a baby

Patient: My period haven’t been on in a mounth and 8 days i had just got off birthcontrol my period came on and 4 days after it went off me and my boyfriend had sex he camed in me and my period have not came on yet i been haven stomch ackes i’am only 15 and he is 13 and i was wondering can i be pregnant and i have bad cramps but no blood..