I NEED HELP BATHROOM ISSUE WITH 4 YEAR OLD

Tonight i feel like i am at the end of my rope.  my 4 year old son hates to go on the toilet for a number 2  at night he still wears a pull up because he is a heavy sleeper which is fine with me but he waits all day then goes number 2 in teh pull up . well today we knew he had to go and put him on teh toilet like 5 times and he said that he did not have to go then i went into his room and he did it in his pants oh my god i was mad ( trying not to look mad )  so i cleaned him up and that then he went number 2 in teh toilet just a bit .  is this normal and does anyone have advice for me i am going crazy and he is going to school next week i know that he will hold it all day but its not good for him to do that what can i do HELP