Hello, I Had A Medical Abortion About A Year And

Hello, I had a medical abortion about a year and a half ago. Since then, every time I have sex, it is almost like that sex induces my period. I am not bleeding right after sex, but a day or so later it will come. I went to the doctor and had a full pelvic examination, which everything was normal and a transvaginal ultrasound that was also normal. Could this bleeding be because of the abortion?