Hi Cers, didnt want to read and run, not completely certain but I occasionally have cramps either before or after a braxton hicks and it is basically the body preparing for labour, it doesn't mean it is imminent unless you have the cramps for a long period of time (not sure if 40mins counts or not) and combined with a braxton hicks that lasts similar length of time...tbh would keep an eye on it and get yourself seen tomorrow if still having pains as better to know for sure...hope this helps...