Okay what were you using?? my guess is that you scraped the inside of your vagina....that will cause blood...and could be sore....watch for any discharge that you may have...if it was a vibrator i sure hope it was clean..or anything that you use should be clean...its not hard to pick up bacteria down there...just my info..have a nice day <IMG SRC="http://www.healthboards.com/ubb/biggrin.gif">
It's possible...did it feel like you were stretching? If there's no pain, I wouldn't worry too much. It you are a virgin, there is always a chance that it was your hymen.