Lower back pain after intercourse is a non-specific symptom, and it is not possible to determine whether or not you are pregnant based on this symptom. Common causes of back pain after intercourse include chronic inflammatory diseases of the cervix such as cervical hypertrophy and cervical cysts, which stimulate the cervix during intercourse and cause back pain after intercourse. If the patient’s uterus is in the posterior tilt and flexion position, the symptoms of postcoital lumbago will be more obvious. Suffering from chronic pelvic inflammatory disease, endometriosis, ovarian cysts and other gynecological organic diseases will also cause obvious symptoms of lumbar acidity and lumbago after intercourse. If you want to confirm whether you are pregnant or not, you need to take HCG or urine early and early pregnancy tests to make a clear diagnosis.