My bullmastiff had her first heat at 11 months and we had her penned in a large cage like a little motel unit, (she is very spoilt) However a large dog came onto our property and completely tore the gate off and got to her. We took her to the vet and had a chat and decided to let her have the puppies as the other dog is a purebred as well. Now she is 67 days into her pregnancy, very large but happy and healthy and still eating heaps. The puppies are kicking heaps and no signs of illness at all. We have taken her to the vet because I am so worried something is wrong but because she and the pups are healthy and not stressed they said to wait and let nature take its course. I need reasurance, can anyone help me?? She has had jelly like stuff from her vulva for days now but its not coloured.
So worried, please help??

If she doesn't appear to be in distress then I would 'let nature take it course' for now.
It's common for even professional breeders to get the due date wrong, or simple not know the exact due date due to multiple matings.

If she appears to be in distress at all, or losing discharge for a prolonged period get her into the vet so they can induce labor.

Has she started nesting yet?

Thanks for that. No she hasn't started nesting yet. I was just hoping it wasn't because we are so close. She is just the best friend and best natured dog I have ever had and I guess I am just worried she won't know what to do being so young. She has a large whelping box all ready and goes in there often but just sleeps. She has milk as well. We have the dates right as this was not planned at all being so young. We we going to breed her after 2 yrs old. I kept the dog that 'violated' her and advertised him until the owner came to get him. He will pay for any medical issues needed which is great as well. And she is just ferosious with her eating still. Just hungry all the time! And sleeps most of the day away but that is no change from her when she wasn't pregnant. I still exercise her daily as well but only as much as she wishes to do. Every little noise I hear during the night I get up and check her just in case she's started nesting but not as yet. Today her vulva is a lot larger than yesterday so hopefully that is a start sign?

Sounds like she is getting close. Increased appetite is certainly a sign. Have you been taking her temperature? If not, get a rectal thermometre and check every so often, if her temp is below 99 then that's a pretty surefire way to tell.

You should be fine though, just from what you have said so far it sounds like you have done plenty of research.
There is no exact science with whelping puppies, every b*tch is different.
We have had some that showed no signs at all and just popped out a puppy on the couch, others started nesting a day before the pups were born.

You vet is your best friend at this time. Don't be afraid to give them a call and ask questions, they will let you know if they want you to bring her in or not.