hi personally i would leave it till after baby is born as he is not showing any signs. I started potty training when my twins were 26 months as they were showing signs, they would tell me before they went for a poo, would wee in the potty and didnt like being in nappies. it is not unusual for boys to be nearer 3 and with the upheaval of a new baby i think it would be best to wait until you have everything back to some normality. I have another baby due in dec and have been warned that the boys may regress and have accidents.
xxDBxx