Why I didn't get withdrawal bleeding while using Zoely?

I've been taking zoely for 5 months, last month I took the pills continuously without placebo pills, I immediately went to a new blister to avoid my period due to a visit to the gynecologist. This month I took placebo pills but I didn't get my period, what could be the reason? I will add that after I finished taking the placebo pills, I moved on to a new blister and took the first anti pill.