Hello I Have PCOS And As You Know It's Hard

Hello I have PCOS and as you know it's hard for me to conceive. For the past 6 months I've had my menstral on time (The 18th of each Month) and it's lasted for about 7 days each time. At the end of October I had intercourse with my fiancé however; I received my period in November on the 18th. I still have yet to recieve my period for December. Could there be a possibility that I'm pregnant even though I received my menstral on November?