Delayed Period, Swelling, and Abdominal Pain: Possible Causes and When to See a Doctor

A missed period with bloating and pelvic pain has several potential causes. Pregnancy is the first consideration, but gynecologic and gastrointestinal conditions can mimic these symptoms.

Differential Diagnosis

1. Pregnancy: Urine or serum β-hCG test. Ectopic pregnancy must be ruled out if pain is unilateral/severe.
2. Hormonal Imbalance: PCOS (oligo/anovulation, hyperandrogenism), thyroid dysfunction (hypo/hyperthyroidism), hyperprolactinemia, perimenopause.
3. Ovarian Cysts: Functional cysts (follicular, corpus luteum) often resolve spontaneously; complex or persistent cysts need follow-up.
4. Endometriosis: Cyclic pelvic pain, dysmenorrhea, dyspareunia, infertility; may cause irregular bleeding.
5. Pelvic Inflammatory Disease (PID): Often from untreated STIs (chlamydia, gonorrhea); fever, cervical motion tenderness, abnormal discharge.
6. Uterine Fibroids: Can cause heavy/irregular bleeding, pressure, bloating.
7. Gastrointestinal: IBS (bloating, altered bowel habits), constipation, ovarian cancer (rare but considered with persistent bloating).
8. Stress/Lifestyle: Significant weight change, excessive exercise, travel, emotional stress disrupt HPO axis.

Red Flags for Urgent Evaluation

• Severe unilateral pain + positive pregnancy test → ectopic pregnancy (emergency).
• Fever + pelvic pain + discharge → PID.
• Rapidly enlarging abdomen, early satiety, weight loss → ovarian mass.
• Heavy bleeding with clots, anemia symptoms.

Recommended Workup

• β-hCG (quantitative serum preferred).
• Pelvic ultrasound (transvaginal optimal).
• CBC, TSH, prolactin, androgen panel if PCOS suspected.
• STI testing (NAAT for chlamydia/gonorrhea).

Do not self-diagnose. Timely evaluation ensures appropriate treatment and peace of mind.