In my case, I just had to hold my X-ray(everything else has been done), then got BC.Medical.
Not really know, because my husband processed everything.
However it is possible to get BC.Medical in advance.
We have started before we come to Canada, means from Japan.
I was about 5-month pregnent when we arrived, then first couple-times visit at doctor, we paid cash, so my husband sent letter to explain, wife is pregnent bababa...
I do not remember how long I waited, but maybe less than a month.