77 days waiting time is amazing!! Congratulations!
We submitted on March 06 and are still waiting in the ".. Receipt Notice Was Sent" status.
I tried to get through to a real person on the phone but the best I could manage was a chat with an associate at USCIS about 5 weeks ago.
They couldn't give me an update on my case but did tell me they were only just getting to the applications from January.
The waiting is the worst... all one can do is breathe!