Your doctor will be able to tell you if they do a physical on you.

Get a hand held mirror, spread your libia apart and look to see if the vaginal opening is bigger than a dime (shouldn't be larger than a quarter, but may be). If you still have your hymen intact, you will see a hole with a skin membrame surrounding it. If you don't see membrame tissue, (it's useally very noticeable), your hymen has been broken.