Baby Physical Development: Infant Left-Handedness
Maybe, maybe not. Most infants use one or both hands for activities as they develop motor skills. Handedness is more often determined after age 2. As a parent, you should allow your child to use whatever hand is comfortable for activities during baby's physical development.
Many left-handed children have grown up in a world where they are taught skills (writing, throwing a ball, etc.) by right-handed individuals, therefore adapting to a right-handed world. If you notice your child using his left hand predominantly, it is important to acknowledge that there are many ways to perform the same skills.