I am 31 and never been pregnant. My last period was September 10th it lasted 7 days which is normal (spotting for 2 days light to medium flow then back to spotting with no cramping). I don't know when I ovulated but my period came again on the 1st of October no spotting, cramping and really heavy flow with large clots from start to finish (7 days) ending today. I had unprotected sex after my sep period and before my oct period I don't think I am pregnant but would like to know if this is normal.

It's very normal. Doesn't sound as though you are pregnant since you did, indeed, get a period for the month of October.