my son is 3 tomorrow and still not potty trained.. I have had him in underwear for 18 straight days…

my son is 3 tomorrow and still not potty trained.. I have had him in underwear for 18 straight days and have given him rewards for going and have got him excited about when he goes.. problem is he is still having a TON of accidents and doesnt care when he does nor will he tell me on his own he has to go.. I'd love to get him out of diapers before the baby gets here in may.. any tips? I shampooed my carpet today and I think I need a break!