There are times that babies want the comfort that comes from sucking but aren't hungry. If your baby is sucking for comfort, their sucking pattern will be different. There is sucking but rarely any swallowing. The rate may start out rapid and then slows as your baby feels comforted.
It's OK to offer your breast or finger or your baby's hand for comfort. It is best to delay offering a pacifier until latch-on is effortless and your milk is well established. The more time your newborn spends nursing in the first weeks of life, the more milk you will make. Regular pacifier use in the early weeks may affect milk supply and cause slow weight gain.