What Causes Bleeding After Intercourse, Lower Abdominal Pain And Back Pain?

hi doctor, am Eva, 40 years old, 5' 7inch tall 90kg. one week ago i had sex with my husband but to my surprise i bled. i have never experience this before, though I have been having lower abdominal pains and back pains in the morning for some tome. i have not sort help from any gyno towards the pain and the bleeding. apart from that i dont have any key medical history worthy pinpointing except form headche which is on very diverse occurance.