Please help? TMI maybe

I had my normal period on June 7th. Been having lots of sex with my SO I have had my tubes tied for 10 years so no condoms. Had bleeding again June 22nd. It was period like. Then now again on July 6th it started again. I went to the ER. They said my urine shows a UTi. They took no blood and gave me antibiotics. The did a transvaginal ultrasound and abdominal ct and saw nothing out of the ordinary. However I have never bled like this from a uti. What am I missing. I have an appointment next week.