Strange/multiple IP addresses from my iphone. Normal or hacked?

Let me preface by saying I have almost ZERO tech knowledge. So… gmail has that little feature where they tell you the last activity in your account, right? And my iPhone is sync’d with gmail via IMAP. So everytime I use my iPhone gmail, I’m getting the “last activity was at IP….” message, and each time—- it’s a different IP address. I used an IP lookup website, and those IPs are coming from the Chicagoland area. I live in NYC.
Should I be concerned about this or is my IMAP/iPhone mail coming through some sort of relay in Chicago?
I sincerely hope that all made some kind of sense.