peeing blood

Just wanted some opinions on this topic, couple days back I had sex and of course I went to go pee after but when I wiped I had seen blood at first I just thought it might of been my period starting so I put a pad on, next morning I woke up and there was nothing on it but when I peeped again there was blood when I wipped, I already made an appointment but am just really scared any thoughts on what it could be ?