I Had A Period May 28 2016. And Had Sex

I had a period may 28 2016. And had sex with someone on June 3rd/4th (midnightish) we did have a condom on. I then had unprotected sex a week later and he did not pull out. My fertile window would have been June 7th to the 16th. What are the chances the first guys condom broke and sperm stayed inside? I'm sure I'm pregnant by the second guy but just curious of the chances.