So I Switched My Birth Control About 7-8 Months Ago.

So I switched my birth control about 7-8 months ago. The name was lo media. When I started taking it, I didn't get my period the first month which I heard was normal with this pill. The next 5 months I was getting it every month on the last day of my sugar pills, but recently I missed my period for about 2 and a half months. I took to pregnancy tests that came back negative and went to the doctor to switch my birth control. My doctor said they're could've been a lot of hormones that completely stopped my period, but I would like a second opinion on what it happening right now.