If you completed your K-1 medical and the DS-3025 was signed off as complete, and you filed your AOS within a year after doing the K-1 medical, you do not need an I-693. This is very clearly explained in the I-693 instructions, on pages 7 and 8 (https://www.uscis.gov/sites/default/files/document/forms/i-693instr.pdf).
So either your K-1 medical was incomplete, not properly signed off, you filed your AOS very late, or whoever told you that you need an I-693 is wrong. It is generally recommended to make sure to complete the K-1 medical to avoid having to redo the medical in the US. There are only a few cases where it would make sense to not complete the K-1 medical (for example, postponing certain vaccinations due to pregnancy).
For the record, I did the K-1 and AOS. But everyone else here also understands this process. It is not that complicated and the instructions are very clear.