Can a 3 month old teeth

Yes. My 3 month old is currently cutting 4 teeth

it is possible to start the teething process that early

That's so long

Yes. Although, my baby showed all signs of teething (drooling like crazy, red gums, looked like teeth pushing up, chewing on everything) at 2 months and they didn't break through until 7 months

my son is two months old is already teething so yes