I have been visiting a friend for a month (they have cockroaches). I'm leaving in a couple of days and traveling home, a 12 hour trip. Last week, I put 1 suitcase in the car, another suitcase is still inside the house along with a couple cloth type bags full of stuff. I didn't think about "traveling roaches" when I put the first suitcase in car.
It is good that you are thinking about this before you leave and before you unpack as roaches are not a respecter of property and will hide in almost anything.
I would also add that it might be best to wash or clean anything that you brought from their house.
Wow! It seems that others did a great job of answering your question! When I moved into my apartment several years ago, there were some baby roaches leftover from the previous tenant. I bought some Combat gel and placed it in the areas given in the instructions. It was mostly in crevices, corners, under the sink, over the doors, etc. A few days later and no more roaches. So, if you do happen to bring home a roach, definitely buy this gel!
Unpack as soon as you get home. Look carefully to see that there are. I roaches. Spray the suitcase after u packing just in case there are eggs in there
Keep your bags off the floor and closed.
Spray all around your stuff with good bug spray
Unload your stuff outside if possible.
If you see any thing after you get home, set off bug bombs. These work really well.