I recently switched from ortho tricyclin to Zovia and continued the sequence of taking my pill without any breaks. I normally would get my period on my 3rd placebo pill, however on that day I receive the FAINTEST (hardly noticeable at all) apperance of blood which went away. I should have had my period on Friday so Sunday late night I took a pregnancy test which came out negative. Could this just be the symptom of switching to a new pill and is that common with Zovia? No matter what pill i've been on (which I have tried 3 or 4)I have always had my period on the 3rd day of the placebo pills.