Can Gastric Cause Pain In Lower Abdomen Region?

I'm having a very bad pain in my lower abdomen. It's been going on now for about 4 days straight. I'm thinking it's gas, but how long would that last??? It started just under my belly button and hurt the worst when I put pressure - wearing jeans or coughing. Now it seems to be lower and hurts with pressure - coughing, using the bathroom. It hurts to walk, sit down, or stand up. It is relieved while I'm sitting, but the process of sitting is very painful. On Sunday, I tried taking a laxative as I really don't have bm's regularly. That did seem to relieve some of the pressure, but not all. I started taking gas medicine yesterday, but no relief yet.