I've been having stomach issues for two weeks now - a sour, slightly nauseous feeling that comes and goes but gets no worse. i eat well and exercise.

Gall Bladder: Possibly Gall Bladder inflamed/stones. Usually subtle pain with burping irregular stools. Fried, fatty foods can make things worse. Or could be Ulcer/ Gastritis. Stomach usually feels better when food is in stomach, worse when empty. Another possibility is Irritable Bowel Syndrome-stress related. Initially try antacid OTC bland diet to see if helps. If not, see doc -might need lab+/or ultrasound