Hahaha ...id swap twenty minutes for twenty times though.

You can usually see if your hymen is intact or not, get a compact mirror and have a good look, but you need to know what youre looking for, so 'google image' an intact hymen, i dont think i possess the ability to create a diagram for you

Its more than likely that you dont have an intact hymen, it can be broken from many types of physical activities or the insertion of a tampon.

As for first time sex, yep - lube lube lube, relax as much as you can and go slooow, its not going to hurt too bad, itll just be uncomfortable. Stick to the missionary position, theres not much point in flinging your legs around and making shapes with your partner this early on...plenty of time for that