Central abdominal cramps randomly +after eating?

I am 20 weeks pregnant and for over a month now I have had horrific cramping centered around my belly button. The cramps come almost instantly after eating anything, but they also come randomly throughout the day. They can last several minutes or just several seconds and then disappear quickly. It leaves me doubled over and in quite a great deal of pain.

I’ve seen two doctors and both declined to do any further testing and told me to “keep an eye on it”. My parents keep insisting it’s gallstones but everyone rules that out as soon as I say the pain is in the center of my abdomen. It’s greatly affecting me, especially at work where I cannot be randomly doubling over and asking people to leave me alone for periods of time. I don’t know what to do and nothing I’ve tried has improved the situation. Has anyone ever experienced anything like this?