I haven't been on the pill since September. I had my period on December 7- December 12th. We had unprotected sex from the 12th until the 16th. It says I should have ovulated the 19th-20th and my fertile days should have been from the 17th until the 22nd. It is now January 7th and I haven't gotten my period, besides being really tired and my breasts being a little sore I feel fine. Could I still be pregnant?