Ay, jangan risau, at 37 weeks plus, your body is getting ready, so these signs are quite normal lah. The thing that helps most mums tell the difference is this: true labour contractions come at regular intervals (like every 10 minutes, then every 5), they get stronger and longer over time, and they don't stop when you move around or rest, whereas Braxton Hicks are sporadic and usually ease off after a while. The lower back pain, hip discomfort, and nausea you're feeling sound like your body is preparing, which is good sign at your gestation, but since every mum is different, I do think it's worth a quick call to your doctor or hospital to check, they can assess properly and put your mind at ease, especially since you're a first-time mum and still learning what to expect. In the meantime, try to rest well and keep track of when the tightness happens and how long it lasts, that information will actually help your doctor lots. Take care of yourself, and all the best with your delivery soon!