Yes I did. I will call my mobile provider to see if any changes were recently made.
I originally didn't suspect a SIM swap attack as I received a text message from one of my contacts around the time the e-mail address was changed. I was out of town of course and did not have my data on. I saw the Twitter e-mail notification the following day. Checking with my mobile provider will be a safe bet for sure.
Thank you for the info.