Hymen help!

[http://users.livejournal.com/-whatnext/]

I've been putting off intercourse with my partner because timing and location are difficult for us to come by.. the only place that is really feasible for sex play is a car, and I really don't want to leave a bloody trail behind. Particularly if it's not my car!
I have a history of gymnastics, dance, horseback riding, sports etc., as well as heavy masturbation. From these factors alone it would seem that there is very little likelihood of my hymen still being intact. Still, I want to minimize the risk.

So my question is, how can a woman tell if her hymen is broken or not (or if she even has/had one?). Is it possible for me to just break it so it will be out of the way?

Edited to add: For what it's worth, I'm also a regular tampon user.




*I've been following chains of links from the userinfo page outward, and can't get my hands on any faqs, archives, or memories! So, even though I'm sure this topic has been perused I hope I won't step on any toes by reposting :)