you're right to worry about your hair , and anyone being sarcastic, probably isn't. there is no such thing as TOO EARLY to hop in action, i'd say you consult a dermatologist and eventually run the blood test, i assure you though, you are not even close to the word hairloss. so do not panic, but do check on a Doctor, if it turns out to be male pattern baldness (androgenetic hairloss, hereditary), you would be exteremly early and thus would suffer insignificant to no loss, most likely.
now as for treatements if that's the cas, you're a bit young for finasteride(a drug that lowers dht, a hormone derivative of testosterone that causes the problem) as it could -a small chance- cause nasty sexual side effects(messing with male hormones obviously isn't risk-free) and i would personally suggest you stay away from minoxidil (spray or foam that stimulates hair growth, or to some extent,slight regrowth) as it may, at the beggining cause a shed(supposdly not permanent) that would make you panic and think you're losing your hair, which is supposed to grow back after, thicker and stronger, and hopefully more hair, but then again would minoxidil make you shed you'd panic like hell, and honestly, you currently haven't the slightest reason to start any treatement. i only mentioned the above to inform you about the situation. by the way, finasteride and minoxidil are the only scientifically proven chemical substances in existance to affect hairloss, anythig else is scam and pure deception, be wary. propecia is the leading product based on finasteride, rogaine is the leading product based on minoxidil.
BUT DO NOT DO ANYTHING , NOTHING, DO HOWEVER CHECK ON A DOCTOR ASAP. if there were anything i'd recommend you do know, it would be to start a healthy diet, and aim for vitamins and minerals in your foods(and perhaps multivitamin supplemnets, though a healthy person needn't) however a healthy diet and adequate vitamin intake never hurt anybody, and it eventually shows in hair, fingernail and skin quality if not for the overall health.
Be healthy, as healthy as you could, and check on a doctor, period, and i pray to god i may never see again you on these forums, for your own sake. hope i helped
I'm seeing my GP today, I suppose she'll refer me to a dermatologist if she thinks it's serious.