Late periods for no reason at all , help

Aimen

This never happens to me , my period is always on time. This time it was due during my exams and given I wasn’t tense , I was using no medicines , I haven’t had sex I don’t get why my period is 20 days late

I’m usually bloated and in a very bad mood these days

The gynaecologist says it’s nothing to worry about but I’m frustrated

What should I do?