Don't know where in Canada you are going too, but in Ontario you can become a midwife if you were already a Canadian midwife in one of the other provinces, or if you were already one in your home country if you take additional courses and exams.
If you were not at all a midwife, it takes 4 years at university.
Including books, fees, tuition, I would say it's about $8,000 - $10,000/year. No transportation or residence included.
You probably qualify for a loan (OSAP) with your wage as a carpenter. Don't know how much they will give you, but you have to start paying for it within 6 months after graduating (or quiting). You pay about 3%, and let's say that you had a loan of $12,000, if you repay within these 6 months $10,000 you only have to pay interest on the $2,000!
More info for Ontario:
Association of Ontario Midwives | Becoming a Midwife