Baby gums are swollen.

Hey y’all so I’m not sure where to post this but my daughter will be 4 months in about two weeks and for the past few days her gums have been feeling swollen/ puffy. She drools so much to the point her shirts are Soaked at the top( started putting bibs on her) and she likes to chew on her hands. I’m a first time mom so I’m curious if this means she’s starting to teethe. How old was your littles when they started teething? And any teething toys suggestions are appreciated