Hello~I agree with the other poster, seeing a doctor for some labs is the best place to start. Abd pain can be caused by so many things, it is always best to get it looked in to.
If after you see your GP and all is well, then try seeing a chiropractor, you could very well have some misplaced vertebrae in your spine causing the pain, I know I have had similar pain and mine sure helps me. He/she will take some x-rays, read them, and then discuss the findings with you, after a few treatments, you should start to feel better.
Hey listen, It's gonna take A LOT more money going to a specialist when some issues could have been clarified with a primary care physician... see what your local options are... but I really advise not to go to a specialist right off the back. The issue with your symptom is that abdominal pain can mean so many things... I mean start with trying to get regular blood work done. There are different ways you can get around to receive a regular cbc. Also, start documenting your symptoms... location, time of pain, foods you eat, lifestyle habits... anything that can correlate to your issues. If money is an issue, you can possibly shorten the length of the search by being clear with what exactly is going on.