Don't panic. I just looked up progestin side effects, and breast tenderness is one of the listed ones.
Of course you need to let your doctor know, in order to ensure there isn't something else to rule out, but I don't think it's time to get too nervous just yet.
I know you say you've been on it for a while so you don't feel this should happen NOW, but it still could. Your body doesn't totally shut down hormonally just because you're taking progestin; you get the overlap between your own body trying to have normal cycles, and the progestin trying to make your body think you're pregnant. These days hormonal treatment is as low-dose as possible, far lower a dose than when I started out on the Pill. So chances of your own hormonal system having an impact is a lot higher.
We women are born with as many eggs as we get for life. Women who have been pregnant, especially if they breast feed, often have a later menopause because they don't use up their eggs as quickly due to the time spent not cycling.
That is true, but there are many other factors linked to menopause onset. I had four kids and hit menopause at 50. My mother had 8 kids and hit menopause a bit earlier than this - she was 44 when I was born and had already had some early menopause signs. My sister-in-law had two kids while struggling with early menopause - she needed hormonal assistance to get pregnant. Her youngest is now 16 years old and as I said, the mother was in early menopause during pregnancy when she was 34 years old.
Heather, get yourself checked out. it's possible that the dose is a bit too strong. Or not quite strong enough. A blood test will determine what is going on. If your breasts are at all lumpy and you are still only 36, I wouldn't think a mammogram is a good idea, it is of limited use when your breast tissue is still "perky". You need to be withered & saggy like me, for a mammogram to really help.
Marg