Can breakthrough bleeding happen at any time?

Lily

I’ve been on Tri Linyah for 1.5 years now just about. I never had any weird spotting until last month. I had brown discharge for 2 days, 2 weeks before the withdrawl. Now this month I’m having pinkish brown discharge a week before the withdrawl. Is this breakthrough bleeding? What should I do? My doctor is away on vacation at the moment