What Causes Missed Periods After Coming Off From Contraceptive Pills?

Hi my wife is 46 years old & has been taking a low birth control pills for years to control having two monthlies each month. I am a Canadian now living in Los Cabos, Mexico. Our Doctor told her to get off the pills & to see if her body will take to the change & have normal, once a moth periods. Well, she has not had a period for four months, so the doctor had her take a blood test to see if she pregnant. She wasn't & I was operated on, so now, I can't have kids. My problem is my wife' both hands are falling asleep each night & her ares feel a little sore. The doctor gave her pre-menopause pills that she takes each night. Is she hitting menopause already? Is this a hormone problem? I also checked the Carpal Tunnel tests & it seems that she does not have this. Please help, Thanks! Shaun Capadouca