2 month old baby sucking on everything...why?

Charlene

Hi!

My baby is almost 10 weeks now, and she sucks on everything, even right after feeding, her own hand, her forearm, my bicep, my shoulder, my chest, depending on how I hold her...Does this mean she is still hungry or just upset about something? Or tired? I've noticed her yawning almost as soon as she wakes up every time in recent days...Thanks!