Yeah here in the US, Arizona at least, its illegal to force/kick out a pregnant teen. The catch is its hard to stay under the absence rate & they can drop you from classes based on that.
I don't know about Canada, or catholics schools either, however.
Do you have the opportunity to attend online school? I think its really best for pregnant teens.
I'm in my junior year. I have 3 months of this year left that I'm just going to finish, then go to online next year to finish up. I also go to a technical school designed for HS students part time and will stay there. I lucked out because about this time next year I'll have a full career :] its so ideal for pregnant teens, there are many in my area of study.