Upper belly/stomach pains

Hi all wondering if any of you can help me or give advice. Since last week I’ve been having horrible pains upper belly (half way between belly button and boobs) it’s accompanied by on and off sharp pains. Told my midwife and doctor they said maybe stretching pains or something like stomach ulcer or gall bladder but they weren’t sure. It doesn’t feel like the stretching pains I’ve had anywhere else as these sharp pains are very intense. Anyone experiencing anything similar? (Ps 28 weeks pregnant ) thanks in advance x