I am 43, in my head I'm 23 and my body currently makes me feel 63.
Until last year, my periods were regular and didn't give me much bother.They have become more erratic, and I can't remember if I had one last month - certainly haven't had one this month. However, I am bloating up like I'm ready to either ovulate or menstruate - have been this way for a couple of weeks. Other delightful symptoms new for this year are:
Aches and pains - left hip/thigh, neck/shoulders, right thumb
Woolly mind - easily distracted, can't concentrate
Broken sleep - don't usually struggle to get to sleep, but wake several times
Heartburn worse - used to only appear when I was stressed, now it's most days
Anxious and tense
Resting heartrate up (thanks, Fitbit!)
None of the above are really stopping me from doing anything, but I feel disgruntled about feeling knackered and old, particularly when I joined WW and started trying to get fit. Lost a stone, walked a few miles a day, promptly got plantar fasciitis and then bloated up like a blimp. 
I know that osteoporosis can be a problem, but I don't know at what point I need to be concerned?