Why am I losing my hair?

I'm a 15 year old male on Indian descent. Lately, for about a few months now, I've been noticing A LOT of stray hairs everywhere, like on my bed where I lay my head, or on the back of my shirt, etc. Usually if I run my hand through my hair, 2-3 strands of hair come out, and I can keep on doing this and it comes out. It doesn't come out in clumps or anything, just a lot of strays. My hand is usually covered in hair when I shampoo. So far the loss isn't anything noticeable on my head, I do have a lot hair, not shoulder length, but thick. The hair loss is rather noticeable if you look at my bed or pillow though, a lot of strays scattered about. My father isn't bald, nor is his father or my grandfather on my mother's side. I use Head and Shoulder's Shampoo and Conditioner in one. I do have an oily scalp, not excessively oily, but I've been told it is. I'm not under any particular stress, or I don't think so, at least, just normal. I always noticed a few strays when I shampoo and on the back of my shirt etc., but lately it's been more noticeable on areas where I lay my head. I used to have it fairly long, about shoulder length, but I keep it just past the ears for a while now, my hair is still thick and a lot though.