OMG plz answer!! Its about my Guinea Pig!!! PLZ!?

Ok, so about 2 days ago i bought a guinea pig and named him toffee. Just a couple mins ago he was on his blanket and its like he peed out white stuff, I swore he was a boy! I have no other guinea pigs, just him. Now im startin to wonder if hes a girl, because he was around other guinea pigs in the pet store. Plz answer and help me!!!!! It slike he peed the white stuff and out, and then the stuff changed to clear. Is that just reg guinea pig pee? Im freaking out!!