Levels question I've seen a lot of people saying they got their levels checked.... how exactly did…

Levels question

I've seen a lot of people saying they got their levels checked.... how exactly did you go about that? I've seen some people say they got them checked then found out they needed to take progesterone. I've had two early miscarriages but I was still told not to come into the doctor until 8w5d for a regular appointment and ultrasound. Not sure the reason of my miscarriages but I'm just wondering if maybe I should be getting my levels checked too ? is that something you specifically requested from your ob or regular doctor or did they tell you to come in?