Take her to the vet and get progesterone drawn. That will tell you where she is in the process and if she has ovulated. Bitches can vary widely at what time during their heat cycle they are ready for breeding. She may not have been ready yet when she was at the stud owner's, so even if they did "get a tie" it may not have done any good. Progesterone testing now may help answer that.
In the future, it is always a good idea to do progesterone testing prior to going to the stud. Especially if it requires travel. Having to drive all over the country to get your bitch to the right stud is part and parcel of being a breeder. However it makes sense to minimize the time away and ensure you're going at the right time in her cycle, and it is worth it to spend some money on progesterone testing and planning when to travel based on those than to try to guess at when she will be ready to breed.