Bleeding During Sex?

Hello there, i am only 16 years old, but i have had sex with my boyfriend 2 times. We just had sex for the second time today, Feburary 14th 2010. The last time was Feburary 11th. The first time we had sex i didn't bleed like i was expecting, since the hymen breaks and all..but the second time i bled ALOT. It was so much that i started crying. I don't know why it happened, but it's really scary. My first thought was that it was my period...but i just ended that on Thursday. So i ruled that out fairly quick. I was doing some research online and all the information i read was pointing me to STDs. My boyfriend's mom had him tested after he broke up with his last girlfriend because she wasn't too sure about her, and he came back negative for all the tests, So, i know it's not him. I was wondering if this is normal...Should i be concerned? I don't have anyone to talk to about this. D: I have used this site before under a different name, and my topic was one of the most discussed. So i know there are people on here who can relate and help me. I would greatly appriciate some advice or some positive feedback.

But here are some symptoms:

-No bleeding prior to sex
-No Bleeding upon Insertion
-Started Bleeding During Sex
(We Stopped Right Then)
-Bleeding stopped right then
-2 Minutes After, Felt extremly sick
-Dizzy
-Then, i was fine again





Soooo...please, if this is something thats happened to you and you know whats happening, please enlighten me.

Thank You.

----HelloMister