Hi M...
As crazy as it sounds, yes, it is possible that your 3 month old is teething. The important thing to remember about being a mommy is that each child is different. My son ALWAYS had a very VERY healthy appetite. So much so that at his 7 month checkup, my pediatrician told me to begin taking him off of baby food and formula and that I could start weening him towards whole milk. I know this sounds very odd, but it was because of HOW MUCH he was eating in a day. By 6 months, my son had pretty much all of his teeth.. he began eating rice cereal off of a spoon at 6 weeks and never stopped. By 6 months he was eating food.. I mean real food to the point he could even eat french fries, mac and cheese, sandwich meat, eggs, bacon, french toast....etc!!! By 18 months this baby boy of mine was eating steak and pork chops and by 2 he could consume 4 pieces of pizza and a salad for dinner..and was eating two lunches at daycare each day (fruits, veggies and all). It may all sound a bit crazy, but I was a first time mom and figured if he could eat it and it didn't mess up his stomach, then why not.. and the day my ped. told me to put him on table food, I got a raise in income as formula and baby food is so expensive!!! Good luck to you and I would be happy to answer any questions you might have. And just so you know.. .even eating all of that, my child was skinny as a rail and always in slims until he finally filled out around the age of 8. He is now 10 and is perfectly fine, happy and is filling out nicely, but is not overweight for his age. Good luck!
A.