I'd say thats teeth!!!!!!!!!

It depends on your bub.
Mostly, the bottom front ones come through first.
My little vampire, at 6 months, got her second top ones first (not the two front teeth, the next ones along), then got her two top, then her two bottoms.

I hope they don't cause her too much grief. Jazzy got 6 in a month, it was pure torture for us all! Have you got an amber teething necklace? We didn't have one until a few months ago but I'LL NEVER GO BACK! She got her molars without a real fuss, which was GREAT considering the dramas we'd had getting the other