Is this teething?

My baby went thru tt and likely it was the growth spurt phase. Got better a few wks later. I combo feed him and he was also fussy while breastfeeding. I also changed his bottle teat ard 3+ mo as he started to only drink 60ml instead of his usual 160-180ml. Drooling is perfectly normal and putting things in her mouth is her way of discovering things, not much teething at this age. My boy was also doing the same frm 3 mo onwards till now at 6 mo, no tooth comes out yet.