How old is your child? My twins were late talkers. By the age of 2 they both only had about 5 words each. My pediatrician wasn't concerned as she wanted at least 5 word sounds but I was concerned! I had read that by age 2 they should have 50+. It worried me that they weren't talking.
We here in Ontario do not need a doctor referral to call the Preschool Language and speech. I called after our 2 year appt. It's a very long wait (9 months for my son to be seen and 11 months for my daughter to be seen!!) so if you do have any concerns I'd call. No harm in being put on the wait list early enough.
In our wait by the time they were 2.5 they did have a language explosion. By the time they were 3 they were talking in sentences. By the time we were seen for our assessment everything was within normal range of their age but they had pronunciation issues. We are holding off on Speech therapy at the moment and will do another assessment in August. The pronunciation issues they have are appropiate for their age.
I also have a 19 month old but no need to call as at last count he has about 20 words.
I'd say if you have any concerns at all there is no harm in calling and getting assessed. Also because the wait time is long for York region.