Doesn't stop when full...

PhillyGal34

My son is perfectly content with just pacifying on me as long as I will let him.  I can tell when he stops eating because he speeds up his sucking and try to stop him when he does but sometimes I cannot tell if he is just trying to get another let down so I wait a bit and if he doesn't slow down I realize what he is doing.  Am I doing something wrong by allowing that? I know he still gets milk even when he isn't eating and just pacifying and I know he is over full due to that because he will spit up when I burp him. 

 When will he start to know when he is full and stop on his own or does he already know that? he LOVES sucking on his hand ... and me apparently... so I know this is a comfort thing too. Any suggestions?

We are starting solids in a few weeks and I'm worried about him not knowing when is full and overeating between the BM and solids.  

Thanks!