​1. SEVERE CRAMPS THAT AREN'T LESSENED BY OTC MEDS Agonising menstrual pain could signal endometriosis, a disease in which bits of the uterine lining grow outside the uterus. Another symptom is pain during sex or bowel movements.

2. BLEEDING THAT IS MUCH HEAVIER THAN USUAL This may be a sign of uterine fibroids, which are benign tumours in the wall of your uterus that are usually harmless but can cause anaemia. There's a tiny chance the culprit could be a blood clotting disorder or cancer.

Advertisement - Continue Reading Below

3. HEAVIER BLEEDING AND KILLER CRAMPS These two symptoms combined may signal pelvic inflammatory disease (PID), an inflammation of the reproductive organs that develops from an STD such as chlamydia. Another symptom of PID is bleeding after sex. If it goes untreated, PID can lead to infertility.

4. SUDDEN, INTENSE PELVIC PAIN Acute pain in your lower abdomen might be caused by a ruptured ovarian cyst. Pain from a ruptured cyst usually starts on one side of the tummy but then spreads all over your abdomen and feels different from regular menstrual cramps.

—Katharine O'Connell, ob-gyn and clinical instructor at Columbia University Medical Center, NYC

What do you think?