I feel like I'm going to throw up. I have a really bad pain in the middle of my back that is so…

I feel like I'm going to throw up. I have a really bad pain in the middle of my back that is so horrendous it makes me wanna cry and knocks the wind out of me. I can't even describe it and then it radiates to my front and I feel pressure in my stomach and chest and back. I wanna say I'm having contractions but don't wanna jinx myself. I can't breathe when they happen. Haven't lost my mucous plug or had my water break or had my bloody show so I'm really confused. Can you guys help me out?