Am I being paranoid?

My boyfriend turned 18 yesterday and he went to town tonight with heaps of his mates.

I've been worried all night because I don't want him to hook up with any one while he's out, he said he wouldn't and I trust him it's just I don't trust other females and his mates are the type of guys that if anything happened they wouldn't tell me or try and stop it and to make this worse we haven't spoke since lunch time today