Adjusted Service Dates. please read!

So I've been rehired at my work, I was gone for 1 year. Been employed for 3 prior to that. Fast forward to today, I've been granted "adjusted service dates". They changed my official start date to 2014 rather than 2017. So far I've got my PTO accrual increased to reflect this. HOWEVER my question is this. My pay at rehire was a few cents lower than it was starting last time for some reason. And even more lower than what I left at. So I wondering now with my adjusted service dates, do you think it's possible for my payroll to be adjusted too? I'm afraid to ask. 
I feel annoying because BEFORE I started I tried to negotiate pay to what is was before. And they turned it down and I accepted. But now that my service dates were granted to be adjusted to 2014, I want to ask again. I just hope they don't get annoyed by me bringing pay up again. But if it weren't for the special circumstance I wouldn't.