Signs of preterm labor?

I'm 32w3d I've been having cramping and back pain for a few days now but right now my head hurts so bad I've had a headache for 2 hours wont go away major back pain and cramping I dont feel good at all I feel so weak I cant even do basic things like go to the bathroom without feeling weak I cant even eat anything it makes me so nauseous. I have a doctors appointment in the morning just wondering if anyone else has experienced this not sure if its preterm labor signs or not