What could be the cause of a overdue menstrual cycle (2-3 weeks late) ?

... for a twenty year old who is not currently sexually moving?
Answers:

What alternative medicine can back with underactive thyroid?

anything from stress to diet translation to the changing weather. don't verbs about it - this happen all the time - the stupidest things can throw stale your cycle.

Justt got it immediately it back again?

stress, losing freight, or working out/running alot. If it continues - you should see your GYN

Why do I sweat a lot when I sleep?

It could possibly be stress or anxiety. Sometimes when you verbs and think something like it more, you stress out and it just make it worse. At least you know you're not pregant:)

WoMEN HELP!?

Eating different, stress, traveling, or medication. Mine would be because of stress, it take a toll on you.

What method of natural childbirth be named after a French doc who qualified future moms to prepare physically an

Could be stress, anxiety or a coppers in diet and/or exercise. Without more info it's firm to say, but you should run to the doc if you continue to enjoy irregular periods 'impose it could be something a little more serious approaching an ovarian cyst.