Inflammation/infection of the uterus is called endometritis. Being unmarried does not itself cause or prevent it. The important factors are symptoms, sexual exposure, recent pregnancy or miscarriage, uterine procedures, retained tissue, tuberculosis in some regions, or infection spreading upward from the vagina/cervix.

In someone who has never had sexual contact, uterine infection is less common, but pelvic pain can also be due to urinary infection, ovarian cyst, appendicitis, endometriosis, vaginal infection, or rarely genital tuberculosis. If sexually active, chlamydia and gonorrhea can cause endometritis as part of pelvic inflammatory disease (PID). PID can affect the uterus, tubes, or ovaries and needs early treatment to reduce risk of chronic pain, infertility, or ectopic pregnancy, as explained in the CDC PID guidance.

See a gynecologist soon if there is lower abdominal/pelvic pain, fever, unusual or foul-smelling discharge, bleeding between periods, painful urination, or missed/late period. A clinician may do urine and pregnancy testing, blood tests, infection swabs, and pelvic ultrasound. If you are not comfortable with an internal examination or have never had penetrative sex, tell them. Evaluation can often begin with an abdominal ultrasound and external tests; care should respect your consent.

Go to urgent care/emergency now for severe or worsening pain, fever, vomiting, fainting/dizziness, heavy bleeding, a positive pregnancy test with pain or bleeding, or a rigid/swollen abdomen.

Do not self-start antibiotics or insert vaginal medicines/douches. Treatment depends on the actual cause, and antibiotics are used only if bacterial infection is suspected or confirmed. The CDC treatment guideline emphasizes prompt clinical assessment when PID is possible.