Overfeeding a BF baby ?

strawberrytree

Everything I've read says you can't overfeed a BF baby, but I'm worried that I am. My DS spits up a LOT. At least a few times a day, and big spit ups too- he just had some projectile spit up that soaked his pants, a blanket, and DH's shirt, along with a huge puddle on the floor (yay laminate flooring...at least clean up is easy?). He is a snacker who is still nursing at least 10-12 times a day at nearly 5 months old. He's also a happy spitter- all smiles, no crying- so I don't think it's reflux.

What I think the problem is, is he eats his fill and then tries to comfort suck (he loves to suck but hates a paci), but I think I have an overactive letdown so he gets more milk than he needs. Then he ends up spitting up the extra milk later. 

Does that sound like what might be happening? Is there anything I can do help the problem? I'm happy to let him nurse or suck for comfort as much as he wants, but I don't want to keep overfeeding him.