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

... for a twenty year old who is not currently sexually alive?What could be the inflict of a overdue menstrual cycle (2-3 weeks late) ?
anything from stress to diet change to the shifting weather. don't worry in the order of it - this happens adjectives the time - the stupidest things can throw off your cycle.
stress, losing cargo, or working out/running alot. If it continues - you should see your GYN
It could possibly be stress or anxiety. Sometimes when you worry and have an idea that about it more, you stress out and it freshly makes it worse. At smallest you know you're not pregant:)
Eating different, stress, traveling, or medication. Mine would be because of stress, it takes a toll on you.
Could be stress, anxiety or a variation in diet and/or exercise. Without more info it's tough to say, but you should turn to the doc if you continue to hold irregular periods 'cause it could be something a short time more serious like an ovarian cyst.