To be concerned ?

[notallsunshineandrainbows]

No period for 8 days with no sign of it coming would you be worried ?

When I was 27 I got 2 months between periods, and i did pregnancy tests, went to dr and did blood tests too and I wasn’t pregnant. It happened only once.

have you tried a pregnancy test too?

This happened to me twice, one was 40something days and once was about 66 days, both happened a few months apart and I wasn't pregnant either time. I think I was 27/28 at the time. I ended up going to the doctor for blood tests to rule out early menopause and everything was perfect, just the way bodies are sometimes!
The doctor ruled the first one down to increased exercise and the 2nd down to stress (I didn't know i was stressed, but he said stress is more of a chemical reaction that the mental strain we typically associate with it, usually experienced if you're thinking a lot about stuff/are busy etc).
Hopefully, if pregnancy is ruled out as a cause, then it's just something mundane like that, but if you're worried go for tests.