My friend has the same problem! Usually my period is always late so I don’t pay that much attention to it. But hers is always on time. However, last month she was late 15 days. Off course we were thinking and predicting the worst case scenario. But after we have bought the home test we were relieved because it was negative.
So she went to see her doctor and it turns out that she was late because she was sick. Nothing serious, just a cold but it affected her cycle. Doctor told her that it is normal if period skips one month but more than one is not good.
So 8 days is nothing to be worried about if you have used protection during sexual intercourse. If you don’t get your period this month consult the doctor just to be sure that everything is fine.