Am I pregnant?

I had sex September 5 around 2 or 3 am a few hours later I had cramping and sure enough my period started. The first two days of my period were my normal heavy flow. But by day four I had no bleeding. I’m concerned because my period is usually around 6 or 7 days. I also don’t know if the two plan b I took in July is just now affecting my cycle or if it’s the other thing. Please help!!!