Emily,

Actually, by leaving and coming back for several days, that sets your separation date as to the last day that he left.
It is probably totally up to you if you want to allow him to back date to May if he files. I wouldn't .

Also, it appears to me that PA has a minimum waiting period of 90 days once filed, before a divorce will be granted.

Here's where I got that info...

Pa. Divorce Law


READ!!!!

And Emily...
DON"T EVER sign anything without calling Legal Aid FIRST.
You will more than likely qualify for their help.

USE THEM.
It's what they are there for.