TTC # 2 in my 40's late period, Please help

Scenario TTC for baby #2 I have a 5 year old I became pregnant quick in a month. Since feb stop birth control in Jan. My periods have not been regular. CD 33,24,28 lasting about 3 to 4 days. I was on an IUD mirena for 4 years. Then did the patch for a month and nuva ring for a month and stopped the middle of Jan 2020. I have always gotten my period even on Mirena. So because of my opk tests being hard to detect when I ovulated since I always have a peak. The plan was to take clomid when my period started but...My period is 15 days late negative urine. My opk today two solid lines darker then control. Blood test last friday was negative hcg 1. I am of 40 years. I am started get hot flashes last week all day and night but tolerable. I called doctor and now was prescribed progesterone to take for 5 days to start my period. Then on say 3 of my cycle to Take Clomid. My question any similar experience did progesterone work. Just apprehensive if I should start or not.