I have a Shar Pei she's 11 months old now...healthy..been the vets for her needles and been checked out as any othe dog is...but she hasnt had a heat yet.

Ive always had dogs (bitches) and they have all had a heat by this age

One of ours was 15 months before we noticed a season, vet was sure she had one before but it was what he called silent, no swelling or blood etc.

My older bitch had her first at 10 months, Diz was 14 months, they are all different, I wouldn't worry too much