Bring your own bedding is not needed at hostels. In fact many forbid it due to bed bugs.
If you get stuck and need to return to the Pittsburgh Airport let me know. If I have the day off I could shuttle you to Boston. But the county airport should work.
The road that county is on is called Lebanon (pronounced lebanun in Pittsburgh) Church Road. It leads down toward the GAP more or less. I can provide detailed instructions later if needed. There is an
Enterprise at 1409