what milk did you use? Was it pasteurized?
If you used raw milk, then you might be fine.
Personally, I would say to let it go and see what happens. You may be surprised what some wild bacterial cultures might create.
And if your PS goes well, it will become the dominant flavor anyway. You might not get the depth og flavor you like, but it should be good.
That said, I am sort of guessing to a certain degree, as I do not use the commercial cultures.
I have made cheese with yogurt as the culture, which lacks some of the definitive Swiss type cultures, but it turned out well, and tastes surprisingly full. Though it does certainly have some yogurty undertones.