What Causes Vaginal Bleeding During Intercourse?

hi i am a woman of 48 years old, and am going to have a US pelvis transbaginal this month, i have had 2 eptoic pregnacy, tube surgery, then IVF which i had triplets. for the last several years now when i have sex, i bleed fresh red blood, sometime it can be uncomtable. ( DO NOT BLEED EVERYTIME) . I have a IUS fitted 6 years ago, so dont really have a period. would like to no what this procedure would be looking for? i think i had this procedure before in my late 30 and they imformed me that i had firbroids on my tubes and adhesions on my tubes.
thank you karen