As a dental hygienist, I haven't heard that swallowing blood would cause that, but I suppose anything is possible. I would tell you though, to have a thorough teeth cleaning to be sure there is no cement from the crown (or any tartar)under the gum -if they didn't do that for you. Also, when you floss (which you should do DAILY because what you brush off the outside of your teeth with your toothbrush is also between the teeth and under the gums where the toothbrush can't reach, so you are actually "brushing" between your teeth when you floss), be sure you are getting the floss under the edge of the crown (fake tooth). Many people don't do that because they are afraid they will pull it off, and if you don't get under there, all the bacteria from things you eat, etc, will build up and cause your gum to bleed. We have to drill crowns off, so if you pull one out with dental floss, there is a reason and you need to see your dentist about it (decay under the crown, etc), so don't be afraid to get under it! DON'T brush hard! Brush gently, but spend some time in that area (not 3 seconds like most people do!). You can also dip your toothbrush into Listerine that has been diluted with water, and massage the Listerine into the gums around the crown to help with the gingivitis. Vitamin C can help, also you might have a Vitamin K deficiency... Have you ruled out ulcers as the cause of the stomach pain in the morning? Excess acid production overnight could make your stomach hurt... You aren't on any bloodthinners (Warfarin, Coumadin, Vitamin E, or aspirin...), right? Smoking can irritate the gums and can also contribute to periodontal disease (bone loss, bleeding gums)... Sorry so long, just tossing out thoughts - I hope this helps!