At this point it will most likely be Pfizer or Moderna. AstraZeneca is currently only used in the pharmacy vaccination program in BC for the 55-65 age group. Everyone I know in BC who works in healthcare, as well as a few aged individuals in the community, has received Pfizer except for those in remote/northern communities who received Moderna.
For what it's worth, none of the ~15 people I know that have been vaccinated (includes ~3 that are 50+) have gotten AstraZeneca. J&J isn't even in BC yet AFAIK.