Ultrasound can be done the day after intercourse. Ultrasound is mainly a morphological examination in clinical practice. Ultrasound examinations are useful in gynecology to understand the size of the uterus, whether there are tumors in the uterus, the condition of the uterine cavity, the condition of the endometrium, whether there are other tumors in the pelvis, whether the ovaries are normal, and whether there is fluid in the fallopian tubes, all of which can be seen through ultrasound. Intercourse will not affect the ultrasound results. It is recommended that if you are having a vaginal ultrasound, it is best to clean your vulva before going to the hospital to avoid local infection. If you have an abdominal ultrasound, it is recommended that you hold your urine before going to the hospital to have an abdominal ultrasound.