Two questions about my upcoming wedding day:

First, I have a heter to use birth control, and was wondering about taking the pill on the wedding day in terms of the fast and in terms of it working. It is a daytime wedding. Can it wait until afterwards and still work? If not, is it okay to take it before the fast is broken?

Second, because it is a day wedding (the chuppah is before mincha gedolah) I will be saying the vidui at shacharit instead of mincha. Is this the only thing that will change in my tefillah?

Thanks for your help.