(Full and normal) Period comes 2 weeks earlier than predicted cycle dates + had unprotected sex afew days prior? 

We used the withdrawal method and he was certain that he didnt come inside me. I know the whole precum containing sperm thing but i was not on my fertile window (we did it around 1 week post period cycle). My period (full bleeding 3 days, slightly heavier than usual, spotting 3 days) came after 1.4 weeks. my period was 1.5 weeks earlier than the predicted date for my next cycle.

what are the chances of me being pregnant? these symptoms are strange so im just making sure. also, are there any tests/things to look out for? (ps dont lecture me about unprotected sex because im 21 and well aware but im just checking)