Speaking of Teeth

Caden fell out of the bathtub about 3 weeks ago. He hit his mouth on the ceramic tile and cut his lip. His teeth hurt the first day, but have been fine since. Last week, I noticed that the main tooth he hit (his left central), is starting to change colors. It was yellower then his other teeth last week and is looking more brown to me now. I hate it. I wasn't able to get him into the dentist until next Monday. I don't know that there's much they can do for him. I'm really concerned about him loosing that tooth before he's old enough too.