I’ve been on the pill for over a year and have been taking it effectively and always at the same time , but because I’m going on holidays this month I’m taking it later on in the day ( due to time changes)

I’ve noticed this week I have been spotting brown, but not a lot. I restarted my pill last monday after my 7 day break but I have only noticed in the last 2/3 days this spotting.

What could it be from?!

This has never happened to me before

(Note: I am in the middle of exams + planning a holiday so very stressed)