i am not agreeing or disagreeing, but i would like to know- what is the source for not being required to make a pidyon after a miscarriage?
also, as far as i know, a pidyon is required ONLY of a bechor. no matter how the first baby was delivered, the second child, even if he is the first boy, would not require a pidyon.
my sister made a pidyon haben for her son many years ago, and i still remember it, because it was such an incredible occasion, because it happens so infrequently.