This actually sounds like a growth spurt to me. They usually go through a growth spurt around 10-14 days, again at 3 weeks and 6 weeks. And even if he is just looking to comfort suck, as long as you are ok with it, it's actually good for your supply to let him suck. If it bothers you, offering a paci is fine as long as you don't notice any issues with his latch. You really can't over-feed a BF baby. The worse that will happen is he'll spit up.