A tie does not automatically grant pregnancy but chances are higher if at least two ties occur. The only way to know the best time for matings to occur would be by doing hormone level blood tests with your vet prior to the mating, however, if she stood for the male, this is a good indication that the timing was perhaps just right right.
Just as in people, no black or white assumptions can be made. if you cannot stand the wait you can have a relaxin pregnancy test done on your dog, this test can be done as early as 20 days after the luteininzing hormonal surge. Best wishes!