Hair falling out

I noticed the last couple of days that my hair has been falling out a lot more than usual. I have medium length hair that I typically wear in a pony tail. The last couple of days when I take down my ponytail I have gotten clumps of hair too. I doubt it's a vitamin deficency cause I have been taking prenatal for months now and never had an issue unless it is an overdose of one vitamin. Is that possible? Thought more likely hormone related. Anyone have this as early sign of pg? Af is due Oct 6 or 7. I thought your hair was supposed to grow thicker when pg. Tested today and bfn but maybe too early.