Were you full grown when you got your period? Most dogs do not reach maturity until the age of 2 or even 3. Remember dogs can get their first heat at the early age of 4-5 months in some cases andin most 6-12 months, a dog is still considered a puppy until 12 months of age.
depends on the type of dog. If its a toy to small size dog most likely yes its fully grown. if its medium dog then it can possible grow a little more. larger dogs to massive dogs are going to grow up until there 2 years of age. Most dogs get there first cycle of heat at 10-11 months old. but its different for all dogs. This is a very rough quote!