hi... im 2weeks late for my period... which is weird cuz ive only ever been 1 week late... im 18... me and my boyfriend had sex n used comdoms... but heres the weird part... my friend and i started our period at the same minute last month... and now we are BOTH 2weeks late... neitha of us have got it...

what could it be?... ive been having mood swings n ive been havin cramps... and so has my friend but neitha of us have had our period yet... if it helps... my friend went on holiday 3weeks ago