You won't have to pay commissions to both buyer's agents. You're actually talking about something different than a protection period.
What you are asking about has more to do with buyer's agency than protection period. If the first agent that showed the home to the buyer did not have an agency agreement with the buyer, then the buyer saw the house with another agent, then the first agent will most likely be out of luck. That first agent will have to file a complaint with the local Real Estate Board in order to be decided as procuring cause for the sale, but shame on them for not having buyer's agency signed. Chances are they will not win the complaint, especially if they lost touch with the buyer between the two showings.
Regardless, you don't have to pay both buyer's agents. It is up to them to fight over the buy-side commission.
RE/MAX Pros, Westlake OH
However, I agree with Kelly, you may want a real estate attorney review your particular contract. Best Wishes to you!
Long & Foster Real Estate, Inc.