I am going to WDW in March with my sister. We are coming from two different states, but want to connect in Baltimore. The times of the connections don't coincide, so my question is this. If I fly to BWI earlier in the day as a direct flight, then take a second flight later in the day and haven't left the airport, do I need to go through security again? I will only have a carry-on bag. I will be flying Southwest. Hope someone can answer this for me!! Thanks.