12grapes

Yes after 2 months this is what USCIS responded to me
The status of this service request is:

Recently, you contacted us about the status of your Form I-751, Petition to Remove Conditions on Residence, filed on January 15, 2019.  On January 12, 2020, you also filed a Form N-400, Application for Naturalization.  Our records indicate that your Form I-751 and Form N-400 are currently pending and will be adjudicated at the same time. 
    Quote

Dang, four years for I-751/N-400 combo cases? I only just filed I-751 a week ago, so I really don't know enough about N-400 yet. However, yes, I've seen some people suggest waiting to file N-400 after the I-751 has been adjudicated to avoid any possible confusion and mishaps on USCIS' part. I've seen a few cases where people thought they were doing a combo interview, only to be told their N-400 file was not transported to the local field office so the IO could not perform the N-400 interview right then and there. In any case, file a request for help through your political representative. It may take a some time, but they have direct lines to USCIS. At minimum, your senators will at least inquire the agency about your case and that will probably get it moving again.

Thank you! I'm in Washington and both Senators are Democrats so we will definitely try that after calling them later. And I've started filling out the N400 form but then I read on here that some people who have the I751 and the N400 pending at the same time in Seattle have waited for over 4 years with no action on their cases, so I haven't actually filed the N400 yet and I was going to wait until I have the 10 year green card, just in case. 

From your signature we mailed in our paperwork the same day and got the text the same day. I havent received the extension letter either yet but it's making me feel better that apparently it's taking forever for everyone.