As far as I know, the reason a woman bleeds when she loses her virginity is because the hymen is broken. It is possible that it didn't break until you intercourse with the second guy. However, I don't think you should be bleeding every time. Consider seeing a doctor if that continues, or consider it right now...
But, because you bled the with the second guy it does not mean you lost your virginity to him. You lost your virginity on Mar. 23 2007. Bleeding due to broken hymen can be caused by horseback riding, excercise. various sports, et cetera. Bleeding does not indicate a loss of virginity.
Also this should be moved to womens sexual health.
*grabs megaphone* MODS!