Pee pee yellow

I'm having a bad day. Stan peed an unusual amount of times yesterday and now I'm spazzing out wondering if he has kidney failure or diabetes or something. (Too much ER will do this to a person). I called the vet and he's going in on Thursday to get his 3rd booster shots, so they'll check him out then.
His pee was clear and he seemed really lazy last night and this morning. He didn't even annoy me while I was putting my make-up on.
I realize that I'm paranoid and he's most likely fine, but I LOVE HIM so I can't help myself.
I woke up about 15 times last night just to make sure he was still breathing.
I'm never having kids.