My period is around 6 to 9 days late and it's sometimes irregular. but it has never been this late before. my boobs don't even hurt.?

Temperamental period: It's likely a female hormone imbalance which can be effected by stress, illness, food intake changes and physical activity alterations. I wouldn't worry too much unless you have had unprotected sex in the last 1-3 weeks. But if that's not the case its probably minor changes occuring in your body that are affecting your cycle.