I Got My Normal Period On August 9th. On August

I got my normal period on August 9th. On August the 10 I took plan b after unprotected sex for 1 minute with no ejaculation and on the 15th of August I believe the pill made me bleed early. So fast forward to August 29 I had sex for a few seconds with no ejaculation again. It is now the beginning of September the 2nd to be exact I have had mild cramps and my regular acne like a normal period is about to start. What could this mean? Should I be worried about being pregnant? Please Help.