22 year old female losing hair?

I'm 22 and lately I've noticed more than normal amounts of hair loss when I shower. There are NO bald spots or patches or anything like that...it doesnt even look thinned out but I'm worried...its definitely more hair loss that what I would say is acceptable. I use a birth control pill, but I've been taking it for 4 years now so I don't think its hormonal. I don't eat red meat, and I seldom eat chicken/turkey. Is it my diet? Overall my body seems healthy.