I had some really intense pains for around an hour tonight. It started with a tightening and stiffness across my lower back and spread to my lower abdomen which tightened too. Felt like my insides were being twisted both front and back and I couldn't stand straight as it was so sore. Lasted maybe a minute each time but I don't know how long in between each pain. I've been struggling with constipation but managed to go pretty normally twice today and it felt different from the constipation pain I've felt before; there was no tightening/stiffness before now, just general lower abdominal and back pain. Could this have been the start of labour? And has anyone had it where their labour stops then starts up again another day?