All the above replies are correct. I just want to chime in and say I am currently on the same boat. came here August 20, 2020, our 2nd year wedding anniversary is on September 25, 2020. But I had to come earlier because my visa expires when my medical expires (September 3, 2020) which was before our 2nd year anniversary. So I had no choice but to come here before our 2nd year marriage anniversary.
So I am filing this Monday since my 90 day window opens this Sunday May 22nd based on my DATE OF ENTRY August 20, 2020 and not our second year anniversary.