when the oocyte is released during ovulation, pain can develop due to rupture of the follicle and subsequent release of a small amount of blood and fluid that irritates the peritoneum.

Sudden left lower quadrant pain and an enlarged left adnexa; in reproductive-aged women with these findings, initial evaluation includes a pregnancy test and transvaginal ultrasound to rule out gynecologic emergencies (eg, ectopic pregnancy, ovarian torsion).

negative pregnancy test and an ultrasound that shows a simple ovarian cyst with a small amount of free fluid in the pelvis suggest a benign etiology.  With the timing of the patient's last menstrual period 2 weeks ago (eg, late follicular phase of menses), the most likely cause of her symptoms is ovulation

Most patients can be managed with reassurance and pain management (eg, nonsteroidal anti-inflammatory medications).

**Mittelschmerz** is a common benign phenomenon in women of reproductive age that is caused by physiologic enlargementand rupture of the follicular cyst during ovulation, which leads to the release of small amount of intraperitoneal fluid and subsequent peritoneal irritation. The pain is self-limited and usually subsides within a few hours to two days. Patients should be reassured and given symptomatic treatment with NSAIDs as needed.

If symptoms do not resolve with NSAIDs, combined oral contraceptive pills (COCPs) can be used in the treatment of mittelschmerz. COCPs inhibit follicular development and subsequent ovulation, preventing the recurrence of mittelschmerz.