Sub chronologic hematoma

I believe to have this and the doc seen it on the ultrasound. Baby is ok for now. Im14 weeks pregnant. I'm freaking out cause I still have brown blood after 3 weeks. Doctor says it ok. It's old. Could it be still coming out after that long.

I'm so scared of mis carrying. Anyone else have this??? I can't seem to think about anything but this. It's so stressful 🙁😰