Is it possible

So I had my second son May 31 2016. I am almost 6mnths pp and I got a period July 7th but haven't since...

I am exclusively breastfeeding i am not on birth control because I have really bad anxiety fearing about my health. I know bc can increase your risk of heart attacks and I am terrified of heart attack i am 26 years old. Anyways my husband and I had sex and its been a very very long time since we had that passion and urge so we had unprotected and he came in me. Is there any chance at all i could become pregnant? I am not worried if i become pregnant jus curious what the chances were.

Thank you