My last normal period was Nov. 21. My fiance and I had unprotected sex on Dec. 1. I normally has a 26 day cycle, never more than 27 days but when I was supposed to have my next period on Dec. 16, it was late. I didn't start until Dec 19th and It was much lighter, especially the first day with just a little spotting, and it only lasted 2 full days when normally it lasts 4-5. I took a HPT on Dec 24 and it was negative. Could I still be pregnant?