i have had stomach pains for over an hour ?!

I did this, too. If you've ever done any sports to the point where your metabolism is really swell, puberty is whacked and prolonged. At least that was my case. I did gymnastics for 7 years and when I was 13, I started getting the hair and stuff, but it took two years for me to get my period, and in that time I did what you've mentioned. Lol, same bra size and everything, dude. However, I didn't get it until I took a break from sports for about 6 months. If I were to still do gymnastics, my doctor said that I wouldn't start until I was 17 or 18 because of how athletic I was.
You'll know when it says "Surprise!". Hopefully, you'll carry around pads and other equipment necessary just in case you're not lucky enough to have it at your house for the first time.

I'm sorry that the pain will get worse the more you age though... It's lame.

My own experience.

Here's an experiment done on rats that I happened to come across:

http://www.ncbi.nlm.nih.gov/pubmed/2603997

It's pretty much the same as what I was talking about.

I hope this helps :)

And you haven't seen a doctor because?????