What are my chances of getting pregnant (read description please)

My bf and I had sex for the first time and we used a condom. Only his head n s little of his shaft was inside me when he came. He pulled out a few seconds after n finished Cumming. I'm worried that I might get pregnant bc the condom was very thin (trojan) n he wore a condom little bigger than him bc he said it's for extra protection. I read that condoms break without ppl even recognizing n I'm worried that it might happen to us. When I looked at the condom after he pulled out I saw that the cum was still in it tho