question - when did your little one start teething ? My baby is 5 months old 4 days and I’m not sure…

question - when did your little one start teething ? My baby is 5 months old 4 days and I’m not sure if she’s teething or not? She keeps licking her gums and burrows her head into my breast when breastfeeding? She is also having trouble sleeping now and she used to not have a problem. She’s fussy and she really wasn’t a fussy baby before her 5 month mark.. not sure what it could be?? Maybe a growth spurt??