Uy, mama, I really think you need to check in with your OB about this, especially kung hindi stable ang sakit, better safe than sorry talaga sa pregnancy. A few of us mums experienced different kinds of belly pain during pregnancy, pero ang bawat case is different, so kailangan talaga ng doctor to be sure what's going on. Don't worry, most likely fine lang, pero peace of mind mo ang importante dito. Get yourself checked out soon, ha? Take care!