ibelieveinHellnow on "Just found BBs two days ago, help, newbie!"

My worst nightmare came true two days ago.
I am terrified that these things will spread.
Here's the weird thing.
We live in a bottom (sorry, thought I felt something crawling) floor apartment.
The neighbors above us just moved in about a week ago.
We also went to the Omnimax theater about a week ago, too.
So there's three kids in one room. Step daughter (we have sole custody) sleeps in top bunk. We only found the BBs in her bed and not on the bottom bunk? They were camped out on the ceiling by her head board.
Is this normal? There's also a air vent not two feet from their camp. (Well, now it's more of a murder scene.)
I'm thinking we either brought them home from the theater or they're coming from the upstairs apartment?
In panic, we bought encasements for each mattress, bought all the bed bug spray available at Wal-Mart, and traps.
I'd estimate we killed about 20. Different life stages.
We notified the apartment immediately. Of course, they won't come until Monday. So here we are in hell until then, scratching .
They are only on the top bunk.
The other two children have no bites, no signs. We have no bites, no signs. (Just psychosis.)
There were no signs last night.
Tonight, we found two. One small, one...."medium"? On her blanket.
So this is normal? To show no activity for a day or two, then they come back out from hiding?
I'm nervous our spraying just pissed them off.
Yes, of course we bagged and tagged and put any linens in the dryer.
What now??