Sudden Change in flow??

Hey ladies so I am 26, TTC my 3rd biological baby and I have PCOS.

All my life I have had insanely heavy periods, typically pretty regular cycles, and have had 2 babies in 10 years. After my son was born in 2016 my period never came back. I had to use meds to get it going in September 2016 after 9 months of no period.

Since then they have returned to “normal”. Typically 33 day cycles INSANELY heavy, starting with bad diarrhea and brown spotting 24-48 hours before it starts.

All of a sudden in the last 2 months I’ve had such light and earlier periods than usual. So light I thought it was spotting due to implantation and not a period. Ive also has weight gain about 15lbs in two months. This is also odd as I’ve stayed at 160 since my son was born 2 years ago. I’ve been fatigued, forgetful, spacey, indifferent.

I have not changed meds, diet, habits.

I am not pregnant. I took a test today and am on CD33.

Any ideas or suggestion for testing when I go to the doctor? My appointment is in February but I have no idea what to ask about.