Can babies start teething as early as 2 1/2 months?

Ok, my daughter is 2 1/2 months, she has all the symptoms of teething but I thought they don't start until like four months or so. My son got his first tooth at five months, I just can't remember when he actually starting teething. She has the rosie cheeks, slobber a lot, fussy, and stinky poop.