My son is 5 weeks old and suddenly he has began spitting up a lot. I've tried feeding him sitting up, mylicon drops, and burping him more often. This has definitely cut down on the digested spit up. However, he is spitting up undigested milk as well. I think he is just nursing for comfort, not for hunger and getting too much milk. I am not worried about dirty laundry, but when this happens he seems like he doesn't feel well. He will not take a paci and likes to be nursed to sleep. Any ideas on what I can do?