My period just stopped

Kya

So I’m currently 33 and my period just stopped. My tests are negative for pregnancy and I don’t know what’s going on with my body. I did go to the hospital months ago and was told I have a cyst on my ovaries and not sure if that’s the cause. But there’s been times this happened in the past and my cycle would be irregular. I’m not sexually active and haven’t been since December 2019. The doc have given me pills to start my period again but I read about the side affects and not sure did they are right for me. Have any women around my age or younger had/have this problem before?

Side note: Because of my period has stopped I am now experiencing a weight gain and I’m now 171 when normally I’ll be around 150.