I am 35 and for about 3 years now I have black stringy spotting after I ovulate. It last about a week then I have a normal period. My Dr has done blood work to check my thyroid, pap smear, checked for polyps, and I have had both an internal and external sonogram and everything has come out good. I have tried different birth control pills (yaz and Loestrin) and they have not helped either. It is very annoying and has been going on for a while now. I had two kids in my 20’s and never had any problems and have always been regular except for the black spotting.