A.J.
Mine! She didn't really say "no" (and mean it) or even "Mommy" until around 2 years old. Around 22 months I was googling the internet because I was worried about a speech delay despite her pediatrician saying she was fine. Just after she turned 2 it was like she learned a new word a day, it's just crazy how much she talks and comprehends now. I'm sure your son will be fine. And trust me..."no" WILL become one of your least favorite words to hear ;) I should note that at around 22 months I also took away her nuk/paci and had her start drinking from straw instead of sippy cups...not sure if this actually helped or if she just needed time tho.