Probability of pregnancy

Okay so my boyfriend finished in me 2-3 days before my ovulation, 12/07 or 12/08, and again the first day of my ovulation, 12/10. My ovulation period ran between 12/10 and 12/14. What are the odds that I conceived, and when can I take a pregnancy test?

My period is due on Christmas, but can I know before then?