I take the last Teenia pill on Wednesday and I always had spotting on Sunday; now it's Monday evening and the spotting hasn't appeared – does that mean I'm pregnant?

If the tablets were taken correctly (i.e. at fixed times, without delays of many hours, no gastrointestinal diseases occurred in the meantime), I see no reason why their effectiveness could be questioned. Many factors can affect minor cycle disorders, e.g. stress, diet change, intense physical exertion, etc. Also, the use of hormonal contraception can cause disorders, e.g. disappearance of bleeding in general. If you still want to be sure, it is worth doing a pregnancy test. Below I leave useful links: https://www.gdziepolek.pl/artykuly/test-ciazowy-jaki-wybrac-i-kiedy-zrobic https://www.gdziepolek.pl/artykuly/jak-prawidlowo-stosowac-antykoncepcje https://www.gdziepolek.pl/kategorie/leki-na-zaburzenia-miesiaczkowania