The general physician says my hymen is intact and is normal. i am 20 yrs old and a virgin. what are the chances i will bleed on first intercourse?

Pretty good: The Hymen is a vascular structure and will often bleed when penetration of your first sexual encounter occurs.

Theoretically, yes: Expect small bleeding and minor/temporary discomfort. May or may not notice it.

Depends.: Bleeding with first penetrative sex is not well studied and may be due to a variety of issues - degree of lubrication, physicality, and of course the hymen. It might be a 50/50 chance.