Big 4 Background Check - Credit Check

This is a fairly specific question related to the background check for a full-time offer with a Big 4 firm (KPMG) in tax.

I interned last summer with the firm, received a full-time offer, and will be starting FT this fall. My concern is that during the background check the firm may have noticed my credit is not exactly fantastic (credit score of 647). Of course I realize that employer background checks do not allow the employer to see my actual score, but I just want to give whoever may be reading this a general idea of where my credit stands. I have never missed a (credit card or other) payment or had collections against me; however, I have carried fairly high credit card balances relative to my limits (particularly over the past few months) and have taken out a student loan during my last semester of school. Though I am in the process of paying off the vast majority of my credit card debt, I noticed that the firm checked my credit report as of the end of April, meaning they have no way of seeing that I am in the process of paying down my debt. If it helps at all, my overall credit card debt was around $10k (is now around $8k and should be down to around $4k as soon as next week). Historically, my credit score was at or around 700, so the drop to 650 - though fairly dramatic - should be only temporary once I pay off my debt.

The truth is that I had to cover a bunch of unexpected expenses due to my family's financial circumstances (hence the student loan as well), but I am able to pay down my debt and have a plan for doing so (ideally I will not have to explain this to the firm, but I'm hoping this is a legitimate reason for explaining my scenario).

All of that being said, do I have reason to worry about my job offer? Given that my credit report was pulled at the end of April, would I have heard back by now if the firm was concerned? Also, I am expecting all of the other aspects of my background check to check out (good GPA, no criminal history).