Scarleteen

My period normally lasts for six days but the one I've just had was late and lasted for only two days. What could be the reason for this?

Hi Anon,

We can't really say why this is. Periods can vary in their length from time to time, and different factors can affect that.

How regular should periods be? Mine is normally roughly every three weeks but it can vary .

Regular does not mean the same number of days each month. It is actually "regular" for a period to vary in length, when it occurs, etc. What you are describing sounds like you are having a regular cycle. If you want more information on menstruation you can find it here: http://www.scarleteen.com/article/bodie ... anguage=en

There is more detailed information on variation in periods.