You really need to take her to the vet for a scan ASAP so you can know whether or not you need to start feeding her up. otherwise you are risking a very unhealthy, fat, ill, unpregnant dog. You will need ot start worming her in 6 days, but how can you if you don't know for certain if she is in whelp?

I woudln't give her tinned food really. There is not much goodness in it, it is mainly water. If you get her on good pupyp complete dry food, you can give that to the puppies too when you start weaning. Do be aware it gets expensive. Our bitch and pups cost up to £80 a week to feed at one point.