Is bleeding at the second blister of Vines after passing a placebo normal?

Hello. I have been taking Vines tablets for a year now. The last two packs I had to take without interruption on placebo due to the omission of active tablets according to the leaflet. I am currently in the process of another pack of 19 tablets today. I had a tribe at 18 yesterday. A few days earlier I was at the gynecologist on a visit all ok without finding out the pregnancy. Is this normal?