VBAC

Hi Mummies, I'm at 39w prego and aware that can due at anytime soon. Starting from 12.30am feeling like having mild contractions and pain getting intense time to time. FYI, I'm I have decided for VBAC and clueless how will really labour pain kicks in. For first child there was no any pain after water breaks till 5cm opening and doc had to induced before ending in emergency C-sec due to fetal distress. Can someone adv when should I go hospital? There is no any other delivery symptoms too.