im 13 and had sex

you should talk with your parent or sibling sister ..  because  you might have to regret it later  if it is a STD ..having sex in your age also sometimes  cause some problems like that . explain everything , so they wouldnt be mad at you . and if you are continuing it use safe methods .. either condom or pills .. but it is not very advicebale  .. try mursterbating rather then having sex 

telling family is not a option

This could just be nothing ,but it could be serious. Talking to family or friends sometimes isn't an option so you should go to the doctors. I'm pretty sure that if you go to the doctors they won't tell your parents and will keep the results secret if you wish. I know     it may seem embarrassing ,but doctors aren't there to judge you and can offer you advice too.

You should go see a doctor though, better to be safe than sorry. It's probably nothing- I honestly don't know, but if you can, try and get in touch with your boyfriend (and ask him if he has any STDs- I mean he has had 5 other girlfriends).

And I know it's too late, but you really shouldn't be having sex at your age -_-".

Hope this helps :).

The bleeding your experiencing could be your hymen ripping during sexual intercourse. Sometimes it takes more than one time to break and rip it completely. Now in my opinion your way to young to be having sex. There is a lot of responsibility that comes with sex and not being able to talk to your parents about it shows a lack of maturity. If your going to be having sex you need to protect yourself and get on some kind of birth control and he needs to be using condoms. Every time you have sex you open yourself up to the chance of catching an STD, getting pregnant, and many other negatives that can destroy your life. Imagine having a baby at 14 trying to go to school and work and then think about doing it all on your own because the babies father left because he was to young to be a dad. Now think about school. What is going to happen when everyone finds out you had sex and lost your virginity at 13? What kind of names do you think they are going to call you? What kind of guys do you think want to date a girl who gets around and is called things like a w****, s***, easy etc? Just because you had sex doesn't mean you have to continue to have sex. My suggest is to start worrying about school and getting a higher education. You don't want to end up on welfare and food stamps living a life you don't want with a kid you will possibly regret.

Now I know this all sounded kind of rude and harsh but its reality and life isn't always sugar coated.