Bitcoin question

So I have 3 withdrawls coming to the same address (well one came already); one from Bovada (already here), one from BetOnline (Processed but not in my wallet), and one from CafeCasino (not yet processed) and I'm not sure if my wallet changes or not when it gets a payment. If it does, what happens if I have money withdrawn to that address after it changes from getting another payment? Does it get thrown away into the void? Do I still get it somehow? does it get sent back to the site I withdrew from and my account recredited? Should I cancel the CC withdrawl before it processes?