TMI What is this?

TMI!

Hi, last week I recently had my period, it was a normal amount and normal cramping. A couple of days afterwards I started to notice small blood spots on my toilet paper, and now the blood looks like this. I am sexually active with my SO Could this be related to pregnancy? Or an infection? I've been bleeding like this for 4 days now, I went to a doctor but she wasn't much help. She just did blood and urine tests. I'm waiting for the urine tests but the blood results were fine. Not anemic nor are my thyroid bad. I had sex with my SO a little before my period started.

My symptoms are nausea, slight dizziness, fatigue, and cramping but not like as bad as period cramping.

Could this be a UTI? I'm probably just freaking out since I have to wait until Monday to get my urine results back.