I'm glad it wasn't anything more serious!
I'm pretty sure that I passed a kidney stone as a teenager - I woke up in the middle of the night in agonising pain and feverishly hot. Being the kind of fool that I was (am?) I decided to wait until lunchtime the next day and only tell my parents and consult a doctor then if the problem hadn't gone away. The pain got so bad that I had to bite on a piece of wood to stop me screaming and waking everyone up. It wasn't a great night ... As it turned out, I peed blood for a while at about 08:00 and the pain went away so I went back to bed, slept it off and I had no further problems.
(Don't try this at home, folks! )