Totally forgot about this thread. Sorry! Thanks for the advice! We didn't end up uploading it.Pretty much what tijanoac said.
If you were not requested by a CO to upload within a 28 day period, do not worry about uploading anything and your medial results will clear in your Immi account automatically within a few days after doing it.
If a CO did ask you for medicals, and it looks like it is drawing to the end of the 28 day upload period, then upload the proof of intention to undergo medical.
Good to hear you have applied for your visa mate!