I've always had issues with my period. Skipping a month or three then making up for it by bleeding for a month. When I was about 21 I went a whole year without a period for no reason. They ran a bunch of tests and did not come up with an answer. About 10 years ago the OB/GYN I was seeing decided that this was too unhealthy (I have never tolerated the pill very well) so he'd give me a shot to start it, then when it didn't quit in a reasonable amount of time, he'd give me another to stop it. I put up with the two shots a month for about 6 months before I said I'm done.

Menopause happens in stages and it can take up to 10 years to complete.