I am 40 and had my tubes tied over 4yrs ago. I have been missing periods and never know when my next one will start. My last period was April 17th, I stared spotting (brownish) and have been for a week now. Today am cramping... any ideas?

I think you should go to the dr.

Could be the start of menopause. Menopause can take years. It usually starts with sporadic periods, just like you described. See your doctor to confirm, or to find out if something else is wrong.

Sounds like you have entered the life of peri-menopause. This can last for as long as 10 years before entering into complete menopause.

For most women the periods get fewer and farther between, but can last longer.