Started potty draining DS this week. (He's almost 3). We've had nappy free time when ever we've been at home and he's learnt when he needs to go. I thought we'd move on to the next stage today, so introduced a pair of pants (as opposed to naked from the waist down). Within 2 minutes of having them on he'd had an accident. He was really upset as it's the 1st one this week. Should i persevere with the pants or wait a bit longer? He is now refusing to put a clean pair on, so don't want to create a negative association 