Windows will sort all of that out for you though... any data sent to your PC from one specific network will be routed to the relevant NIC.
As for having the possibility to have the same IP on both networks, that would only happen in the following cases:
Both of your separate networks are using the same subnet (bad idea)
You manually set a static IP on one NIC that is the same as the IP on the other NIC

Are either of those scenarios ever going to happen?