Between a Rock and a Hard Place

Ok..so it might not be THAT serious...but it's one of those things that we just can't seem to get right. Ryan's nap time. If he takes a nap, he's up till 10:30 PM, at least. The other day he only took an hour nap and he was up till midnight! He's in his bed, but he'll come out of his room multiple times for different reasons. Ie: he needs a drink, he has to go to the bathroom, I forgot to fill the humidifier with water, his thumb hurts, I didn't clip his fingernails, Colin wants to see me (yet he's dead asleep). So there are days like today where I keep him up and his attitude just goes downhill as the day goes on. He gets SUPER emotional over any little "upset". And he just about fell asleep on the way home from church. Now there are days where he does just fine with no nap or with a nap. I just wish there was a better way to know if he needs one or not; instead of this guessing game and being stuck with the consequences.