I also tested positive for the H. Pylori several months ago. I have no clue where I got it - they say contaminated water, feces, etc. I had ulcer symptoms and chest pain for almost 2 years before they found it. The main thing is you have to take all those pills properly - don't miss any! It is also good to have lots of yoghurt now - because the drugs can kill all the good bacteria. Also, the antibiotics made me feel pretty lousy but you just have to keep taking them. If you mess up, the bacteria won't be killed. Good Luck.
p.s. I had no side effects of prevacid. Just a really bad taste in my mouth and nausea from the antibiotics.