Moderator, Omni, Omni/PR, Omni/Games, FlyerTalk Posting Legend
Join Date: Oct 2004
Location: Between DCA and IAD
Programs: UA 1K MM; Hilton Diamond
Posts: 72,452
The situation to worry about would be if you booked the two segments on completely different tickets (e.g. booked a one-way ticket AAA-BBB, then booked another one-way ticket BBB-CCC). Then you could have issues if irrops screw you up at BBB.
However, using the multi-city search will book them on a single ticket, even if they're priced as two one-ways. You'll be fine.