Senescent Endometrial Cells in Patients with Thin Endometrial Lining

The goal of this observational study is to determine if thin endometrial lining that is unresponsive to estrogen might be associated with the presence of senescent cells in patients following long-term use of oral contraceptives. The main question it aims to answer is: Are there any senescent cells present in thin endometrial lining? During the luteal phase of the cycle, participants will will undergo: * Gynecologic US to measure the endometrial lining thickness and pattern. * Endometrial biopsy with Pipelle catheter