Your patient is a 22 year old nulligravida who presents with…
Your patient is a 22 year old nulligravida who presents with a h/o amenorrhea for the last four months. Menarche age 12 with irregularity for first few cycles but became rapidly regular and were occurring every 27-29 days with a flow lasting 3-5 days (Menstrual triad 12×27-29×3-5). She denies sexual debut, previous STIs, pregnancies. She reports a negative PMS and PSH, is on no medications. What is the first test you would perform to aid in your clinical decision making?