Does Taking Tri-Sprintec As Below Offer Pregnancy Protection?

In my sixth month on tri-sprintec. Forgot to take it Tues night of first week, took it early Wed morning, and then again Wed night at usual time (10:30 pm). On Thurs and Fri took it about 1-2 hours later than usual time. Partner and I did not use a back-up method, but packet seems to suggest no back-up is needed. Given been on pill more than five cycles, should I be worried?