Possible early miscarriage, vaginal bleeding more 1 month

(31F) My last period was at the end of June. In July I had unprotected sex during ovulation. My period (which is always regular) didn't come and I had been having very intense and vivid dreams (unusual for me), so I guessed I might be pregnant. I took a test 3 days after my period was due and it came back negative.

Eventually I started spotting 10 days after my period was due, and after a few days it turned into painless but heavy bleeding. The bleeding was different from my normal period - lot's of blood clots mixed with a liquid of egg white consistency, and also some uterus lining.

I've been bleeding ever since (now going on 31 days), although it is not as heavy as the first week, it's heavy enough that I have to change a mini pad 2-3 times a day.

I went to the gynecologist a week ago because I was concerned that the bleeding hadn't stopped. She thought it could be a miscarriage or ectopic pregnancy. She checked my HCG levels (result: normal) and did a pelvic ultrasound. The ultrasound showed there was no pregnancy tissue in the uterus. They found no tumors. My right ovary has some follicles and my left ovary has a unilocular cyst.

She gave me tranexamic acid (250mg) to help lessen the bleeding. I've taken it for 5 days and the bleeding still hasn't stopped or lessened.

Before now, my periods have always been regular. My cycle is 25-28 days, my flow is medium to heavy and bleeding lasts 3-4 days. My periods are relatively painless, with minor cramping and mood changes.

I've never had any spotting or abnormal bleeding like this before. I have hashimotos but my thyroid levels are normal. I am not taking, or have ever taken hormonal contraceptives, but I have occasionally taken the emergency pill. The last time I took the emergency pill was probably 3-4 months ago.

What's going on? Did I even have a miscarriage or could this be something else? Are there any other tests can I request from the doctor to find out what could be the cause of this?