Need some help

37w and 2d... as of 36w and 3d I was 1.5cm dilated, 80% effaced and fully engaged. I had a lot of Braxton Hicks since but then suddenly something changed. For the past 2 days I’ve been feeling really off... nauseous, menstrual like cramping that wraps around back to front that’s persistent and bearable but makes me want to lay down (can’t time it tho), horrid heartburn that medicine can’t fix, headache, tired, pelvic pressure, lightning crotch.. and I just don’t feel myself. I feel out of body and like my body isn’t mine and just completely off. I have a bad gut feeling but I don’t know what it is.. i have an OB appointment on Tuesday. Id rather not go to L&D if it’s not an emergency ya know? My blood sugar/pressure is fine. Im hydrated and full. Baby is doing great so what the fuck is going on and should I be worried?