Your symptoms are seen in gallbladder issues and the pain can vary with different people. The gallbladder typically is on the underside of liver right under the ribcage on the right side. Often it is accompanied by lot's of indigestion, burping, feeling of pressure, like there isn't enough room in your stomach. Sometimes the pain will radiate into the shoulder and shoulder blade area. Not uncommon to raise it's ugly head during pregnancy. It can come and go and may or may not relate to exactly what you eat. Some triggers for some people are fatty greasy foods. Carbonated beverages were terrible for me, I could eat chicken soup, vegetables and have problems, then on the other hand, I could eat chili, spicy foods, pizza and have no problems.
My experience with gallbladder pain was similar to what you are feeling, then several changes occurred and it would be different at different times, but for two years, I kept going to the Dr. with BACK pain. I could take my right hand and place my fingers toward middle of my back and thumb on right side and tell the Dr., "my back hurts right here". TWO years of misery, sometimes I would get sick, nausea, vomiting, indigestion, pressure, etc. I would get shots for the pain, it would go away for weeks and months, then back again.
Finally, a different Dr. (I saw several over the years because I worked with them in the hospital, described my symptoms), told me he thought it was my gallbladder, however, all the tests were normal. This was before ultrasound and CT scans, we had old fashioned, "gallbladder vizualization a GBViz".
I went to a surgeon, had the gallbladder removed and it was bad. I had a "torsion, which the duct was twisted" and it was full of sludge, like syrup with fine sand". I had the open abdominal surgery, appendix also removed and was back to work in 30 days. All that pain and indigestion and pressure was gone!!.
I did end up with IBS and diarrhea for many years, which is common after GB surgery, but easily correctible with the proper balanced nutition and fiber. Of course it took many years to find that amazing fix.
Best wishes, but don't be surprised if the GB is your problem.