If you haven't gone a full year without a period, you aren't in menopause yet. Some women have no symptoms or just mild symptoms of declining hormone levels.
I too, never had a single symptom minus the absence of my period. While my sister has severe hot flashes and other symptoms I just never experienced.
I'm having a similar experience. I'm 51 yo and just went through a 6 month stretch without a period (hallelujah), but then period returned. So, I'm in Menopause (?) But have no other symptoms either.
I'm going to call you lucky!! :>) I think menopause is different for every woman as to how severe and what age. You may not be totally done yet if you are still having occasional periods (even once or twice a year). But that you didn't have hot flashes and mood swings, awesome. Some women do have a milder situation. There are tests they do to see if you've been through menopause. They do blood work and check your estrogen level which should be low and your FSH level which is normally higher if you have been through menopause. https://www.healthline.com/health/menopause/tests-diagnosis I'd get that done and go from there. It may give you the answers you seek.