Scared..plan B

Ok so...my long distance boyfriend and I had unprotected sex lots of the times when he was visiting last month and I used plan b once but obviously I know that it only protects that one time before..and it made me spot for 14 days after and now I haven't gotten my period this month and I have weird stomach pains and I'm kind of dizzy in the mornings and my boobs hurt but I always get bad PMS symptoms so I'm just wondering if I'm being crazy or has anyone else kind of skipped their period the next month after taking plan b with spotting after?? I guess I'm in denial and scared and that's why I haven't bought a test yet...