I get pain in my lower back sometimes, it comes in waves and often shoots upwards and around to my chest. it takes my breath away so I just wait for it to pass, usually after a few seconds. I thought this may be contractions as my pms cramps were always in my back too but my OB says the twins are pressing my sciatic nerve. I'm not convinced. L&D; said to come back if it got worse and more frequent. Would love to hear from mommas who have experienced back contractions/Labour. thank you!