Took canasten pessary for thrush, the next two days i have had unexpected bleeding. due to pessary / thrush or minipill? when to worry?

Probably minipill: Bleeding is an unusual side effect of the canasten pessary--clotrimazole for a yeast infection. Breakthrough bleeding is common with the progesterone-only (mini) pill so I suspect the pill is the cause. Two days is not unusual. If it has stopped, I wouldn't worry. See your provider if unexpected bleeding resumes, especially if it becomes heavy.