Hi Laurad
I haven't used Canagan so I can't help with that I am sorry. I use Purina Pro plan food I move my bitches onto Puppy food at about 4 or 5 weeks If I feel she is carrying a big litter (she is a small breed and average litter is 4) I have left them on adult food if they are carrying a small litter and they are fine. I usually give an egg every other day which they love and is a good source of protein, I was told by my mentor that it helps make good strong membranes (birth sacs) I do not know if this is true but she knew more than I did! for a larger breed it is recommended an egg a day. I have never had any upset tummies with the eggs.
I don't bother with cottage cheese as the puppy food should have an increase in calcium. Also in the last two weeks to 10 days of pregnancy I will move my Bitches back onto adult food to try and prevent Calcium storage which can actually increase the risk of eclampsia.
This is a link to a website that has a week by week guide to pregnancy
http://www.dogbreedinfo.com/breedingpregnancyguide.htmEveryone does it their own way this is the way I have found works for me, hope it helps.