Help?

So I need help! If my period was April 4-7th and I had sex, April 7th w/my ex. On the 17th, OVULATION day, I had sex w/my new boyfriend and he came in me, multiple times. I ended up pregnant, is it possible that I could be pregnant by my ex? Even though sperm only last 3-5 days in your body & it was 10 days in between the last time we had sex and I ovulated?