Alopecia while pregnant??

Alyssa 👩🏼👶🏼👳🏽
First, when I was on the depo shot a few years ago it made my hair fall out, to the point I had bald spots on my head, that did grow back over time. So I stopped the depo. Never had the problem again.. Well a week or so before I found out I was pregnant I noticed at small bald spot right by the front of my hairline, I am now 21 weeks pregnant and the bald spot has gotten huge. I can barely cover it anymore, I have to make sure my hair is a certain way all the time to cover it. 
I went to my doctor for it, and she thinks it's because my hormones. And whenever my hormones get thrown outta whack it makes my hair fall out, which we'll do testing once I have the baby and my hormones get back to normal. 
Any other mommies have this happen?? How did you deal with it? 
I tried tea tree oil shampoo and that hasn't helped much..