Talk to Gynecologist on Burning And Acidity In Pregnancy

I'm 27 weeks plus pregnant. it's my first pregnancy. everything was going smooth no pain n health issues until week ago. I started having lose motion I didn't take it serious then 2nd day I had green lose motion thrise in one day. I went to doctor she advise to have ontex, ORS sachet b cemetac plus stool Dr test . within 2 days lose motion got settled so didn't go for stool test. now situation is okay my issue is now I'm having burning n acidic feeling on n off in my not taking anything spicy or after having water too. sometimes having slight pain in my stomach too but goes off. my doctor appointment is after 2 weeks. can I have any suggestion regarding my situation? is it normal I couldn't go for stool test because their lab requirement was to send sample withing an hour and I was passing in mid night that's why.