CBS are showing repeat episodes on 14th April (Red Carpet Treatment) and 21st April (The Red Ponies). So I think the schedule looks like this:
31st March: 3.18 The Red Mile
7th April: 3.19 Every Rose Has Its' Thorn
28th April: 3.20 Redacted (or may be called In The Red)
5th May: 3.21 Like a Redheaded Stepchild
12th May: 3.22 Rhapsody in Red
19th May: 3.23 & 3.24 (from 9pm)
If in the UK we continue to get an episode every week, this means that the 2 hour finale will be shown only 1 week after it's shown in the US.