I'm 15 and don't know much but I have read a lot of stuff on here... :P
These are really common questions it seems.
1. Is it painful? (It can be if you insert a larger object that you aren't used to.)
2. Is it normal to have the urge to pee? (Yes, from what I read on here it is.)
3. If so should I pee? (You probably won't, but try putting a towel under you just in case. Or try in the shower or something)
4. How long does it take to orgasm? (It varies from person to person. I don't know about girls, but for me maybe 5 minutes, more if I have done it soon before. Probably longer for you but I don't know...)
5. Can I orgasm with a detachable shower head? (Try it, lots of people say it's good, but nothing will work for every single person).
6. Do I bleed? (not unless you stick something large in there and break your hymen. I don't know how large it has to be)
7. If I catch myself getting bored, should I keep going anyway? (it's up to you, I don't know how to answer that ;P)
8. Is there any other ways to masterbate without my mom finding out? (probably, there are LOTS of ways...)
I think that is everything, but feel free to ask more or PM me.
The sensation of wanting to pee is a good sign your going to squirt or have a female ejaculation so just go with the flow but if your on your bed put an old towel down so you dont soak the bed.
Different people take different amount of time to orgasm and also depends how turned on you are when you start.
Yes you can masturbate and orgasm with a shower head once you get to know what to do.
You will only bleed if you stick your fingers or something into your vagina and break your hymen.
If you start to get bored you probably won't orgasm or enjoy it.
That depends really on if your a moaner or screamer when you masturbate.
Hope this helps :-)