Sabrina, it just might be worth getting the vet to check him.
I read somewhere that cats can get a cystitis type thing, and it can cause them to pee more and in odd places. It can be a simple infection, easy to treat and sort out, or it can be an indicator of something more.
My boy Jacob, PTS last year, eventually had a body cavity full of fluid - not pee and not blood - and at 15, the vet reckoned that whatever had caused it couldn't be good news and would need an op, so, given that anaesthetics and old cats are a bad mix, I chose the easy option for my boy.
Much later I read about this cystitis and peeing in odd places thing, and recalled that Jake had had a phase of doing this some months before he developed the swollen abdomen.
Maybe it wasn't related, but you can imagine how much I wish I'd taken him for a check-up back then...