I have this problem too and use the most heavy duty pad and tampon together, and still change every hour. I have the problem also with it being worse every other month. Now while my period only last 3 days at the most, I can't really can't exercise because of the leakage, certainly not yoga and I try to stay at home as much as possible during the worst day. Are you having clots?

I have been to a OBGYN and there is nothing wrong. There are some treatments for this. I can't do birth control meds either and they tried a hormone replacement thing, and I broke out in hives from it. There is some kind of surgical treatment for it too (i can't think of the name right now) You should see an OBGYN, normally you don't need to be referred from your doctor. I would check though. Insurance companies are getting really picky now days.

If I remember correctly, it seems like that the toxic shock syndrome can happen when a women leaves the tampon in too long. Well with your periods, the most it would be in would be an hour. But I understand your worries. Good luck, I hope someone can better help you