Aw mama, nausea and upset stomach around 38-39 weeks ay common talaga, pero since ikaw ay on the brink ng labor at may ganitong symptoms, best na i-mention mo talaga sa OB mo ASAP, hindi siya dapat i-ignore just to be safe, lalo na kung paulit-ulit at kasama pa ng ibang signs. You're doing the right thing by being alert, kaya go ahead at contact your doctor or birthing center para peace of mind mo at para ma-check ka properly, mas maganda na sure tayo, di ba? You're so close na, mama, and you're handling this so well already, kaya push through lang!