Why am I losing a lot of hair ( details & picture) ?

My hair is thin and fine I never really had thick hair but it sure got finer as the years passed. I’m 28years old and I recently went through a miss carriage so I’m thinking is the hormones right now. But even before my MC I was already losing hair.
I try to wash my hair every 3 days. I don’t use heat it wants as much before and no matter what everytime I brush my hair or brush them with my fingers there’s no stop , 3 strains of hair would fall off each time. I don't know what to do. My doc told me to continue taking prenatals for a month. A few weeks they said a was slightly low on iron and I need more vitamin d which I been taking for years. That’s about it. My family does have fine hair history.

from just brushing my hair.
from just brushing my hair.
Why am I losing a lot of hair ( details & picture) ?
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