Condom piece found inside of me

me and my boyfriend has sex and he came inside the condom to joke around because I'm scared of condoms breaking he blew into it a little to show that it wasn't ripped it was perfectly round. later tonight I go into my bathroom and find a lot more than usual white stuff then this a condom piece I instantly start freaking out I'm underage and his dad can't get me plan b help!! I'm terrified