Pregnancy spotting for no reason

Amy
I have spotted my entire pregnancy. For a while I had a subchorionic hematoma which is now gone. Then I was diagnosed with placenta previa, which has since migrated. I have spotted brown for weeks. Now back to dark pink. It's never a lot of blood, but enough to make me worry. What are some other reasons this could happen?
I had an ultrasound yesterday (#6) and they had no answers for me other than I have two fibroids 1.5cm square. Can fibroids make you spot? I'm 21 weeks tomorrow. 

Glow Resources

Let’s Glow

Glow is here for you on your path to pregnancy

Glow helps you navigate your fertility journey with smart tools, personalized insights, and guidance from medical experts who understand what matters most.

25+ million

Users

4.8 stars

200k+ app ratings

20+

Medical advisors