"Does the 3% H202 stop bleeding gums??"

If you're talking about using it as a mouth wash I can tell you from personal experience - no it doesn't.  I used it daily for several years and it didn't do a thing for me - except, it is an excellent mouth wash.  My gums started bleeding during the time that I was using it for a mouth wash.

I have the book "Reversing Gum Disease Naturally: A Holistic Home Care Program" and the very first thing the author tells you to do is to floss daily.  They will bleed more for a while, but might stop after a couple of weeks.  I didn't try it long enough for it to work for me because I went to the dentist first.  If you don't floss daily you're setting yourself up for heart disease.  Sounds weird but the same bacteria that are between the teeth and cause plaque build up are the same critters that get into your blood stream and cause plaque build up on your artery walls.

I finally broke down and paid my dentist a visit (for the first time in several years) and found that my plaque build up was below my gum line and that is what caused the bleeding.  The solution was a deep clean, painful - they numb you up with Novocain, but well worth it.  My gums bled during the cleaning but I had no more bleeding within two to three days after the procedure - and I now floss daily.

My suggestion is to see a dentist and find out what's going on.

Should have mentioned earlier that if you are using anything but a soft toothbrush (hard or even medium) you can easily cause the gums to bleed.  Also with your soft toothbrush - brush your gums as well as your teeth.  This helps strengthen the gums and helps them to stop bleeding.  I switched to a Sonicare and brush my gums every time I brush my teeth.  Gums feel great afterward.  Any soft electric brush will do the trick.  I also use a Waterpik which helps strengthen the gums too.

Here's an excellent site on suggestions in relation to bleeding gums:

http://ask.metafilter.com/65561/How-to-combat-receding-gums