Coffee and Caffeine FAQ

Hi everyone, I am 31 years old and a huge coffee drinker. I've been drinking coffee since I was a kid. Well I have a question I hope someone can help answer. Lately I've been drinking coffee every morning and noticed after drining my first cup or second cup, my stomach would began to tighten up and begin cramping. I of course love my coffee and drink more. Then I have to run to the bathroom.
I was wanting to know, by me drinking so much coffee, could the caffine be messing up my stomach and causing serious harm? I'm just worried about my health, because i have a beautiful son that was born Christmas day last year, and I want to be healthy. Me being a coffee lover, I hope I'm not going to have to quit. I did hear coffee causes ulcers.