Five months missed period on birth control, negative pregnancy tests, what is going on?

Patient: Hello- I have been on birth control for over a year and a half, since we got married bascially. I have tried a couple different kinds and am now currently on the generic version of Yaz. Previously I would have my period before the sugra pills, so I would break through bleed. But about 5 months ago I stopped getting my period all together. I have taken countless pregnancy tests all coming up negative. I believe I recall my previous doctor saying to me it was ideal that i would no longer get my period on the pill. I thought that was weird. What is happening to my body? Am I ok?

Doctor: