My cat is having babies but I don't know how far she is. How soon can you feel the babies move.

Just go to the vet

As simple as the above answer is it is so true.

If you don't know enough about breeding cats then you shoujlnd't be doing it.
Get her checked out by a vet and have an x-ray done to find out how many kittens she is having.

Seeing as how you don't know when they are due I would say it is an outside cat?
Please get her spayed after she has this litter.