Question

Seeking evaluation for worsening fatigue and irregular vaginal bleeding, a 46-year-old woman presents to the gynecology clinic. For the past eight months, her menstrual cycles have become highly unpredictable, varying from $21$ to $45$ days in length. When she does menstruate, the bleeding lasts up to $10$ days and is extremely heavy, often requiring her to use two maxi pads simultaneously. Her previous cycles were regular, occurring every $28$ days. Her medical history includes type 2 diabetes mellitus, obesity, and hypothyroidism. Her current medications are metformin and levothyroxine. Vital signs include a temperature of $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), blood pressure of $135/85 \text{ mmHg}$, and heart rate of $88\text{/min}$. Her BMI is $36 \text{ kg/m}^2$. Pelvic examination demonstrates a normal-appearing cervix; the uterus is normal in size, mobile, and non-tender without palpable adnexal masses. A urine beta-hCG test is negative. Laboratory studies reveal a hemoglobin concentration of $10.1 \text{ g/dL}$.

Which of the following is the most appropriate next step in the management of this patient?