DS is two and a half weeks old, an enthusiastic feeder and gaining weight well. He often seems to overdo it a bit with the breastfeeding though and throw up afterwards - so I wonder if he sometimes sucks for comfort and takes more milk than he needs? For example, he'll sometimes feed for an hour taking both breasts, fall asleep for 10-15 mins, wake up and go back on the breast but then throw up after 5 minutes. He doesn't sleep a lot compared to what the books suggest a baby of his age needs, and often wakes up after 10-20 minutes of napping and needs either a nipple or finger to suck to get him back to sleep.
I wonder if a dummy would help him sleep longer/better - but understand guidelines suggest waiting til 6 weeks. If he's feeding well, and we haven't really had any problems with breastfeeding, is a dummy really likely to interfere?