K.M.
Pacifiers are just fine for babies. Research is actually starting to suggest that babies who use them have a lesser chance of sids. My son sleeps with one - and now especially when he is teething, he likes having something in his mouth. With my daughter, we gradually took it away - starting with allowing her to have it in the car and for sleeping. Then it was just sleeping, then only at night ... and finally, when it was thoroughly chewed, she through it away herself. At 4 months, just enjoy the sleep and soothing he gets from it!