I woke up and felt a little pain on the back of my tongue like if i had bitten it and i felt it it waz a little bump and i have had oral sex last week

Oral trauma: Perhaps you did bite yourself while you were asleep. But since you added info about oral sex, I assume it was unprotected and that you realize you may be at risk for sexually transmitted diseases/infections. Best thing to do is to go see your Family Doc or your local city/county STD clinic. Planner Parenthood can provide STD care too. Check out http://goo.gl/G5IQfj for more info.