I haven't had my period since the middle of march and I never had it since, what could be wrong, I`m not pregnant as I never had sex, what could I do without going to my doctor, my friend is taking iron tablets ever since hers stopped and she has hers now, would this work for me, or what else should I try

How old are you hon?

If your still young, its very common for a girl to have unpredictable/irregular periods.

You should see your doctor, even if there is nothing wrong, he needs to be aware of what is going on in your body.

Don't take the iron unless you need it as an iron overload can cause health problems. You need to go see your doctor. And act like a mature girl and take some responsibility for your own health.

When I was younger I had the problem. My doctor put me on the pill and it really helped to regulate things. I never knew when to expect my period before that. It would surprise me every time.

Taking supliments, particularly iron, without a doctors supervision can be dangerous. If they worked for your friend it could be because she's anemic and/or underweight. However, it could be a total coincidence as well...

You really must see a doctor about this or you'll never know for sure.

Periods can stop for a multitude of reasons, including:
Pregnancy,
PCOS (Poly cystic ovary syndrome)
Endometriosis
Cysts
Bad Nutrition/weight issues
Stress
misc. illnesses
Normal hormonal fluctuations (depending on age)

Until you find the exact cause, self-medicating with vitamins/suppliments will not only be a waste of time and money, but could potentially be dangerous.

On a personal note: I took B6 when I was trying to self-treat my spotting issues and I actually over medicated and had severe side effects to deal with for 2+ weeks. All that and I had only taken the "recommended" daily dosage that was on the bottle.