O.A.
Another possibility--but I don't know about your situation. Two years ago, at age 36, I started having very similar experiences every month prior to my period. I began spotting lightly for 2-5 days each month before my regular period started. Since I had never experienced anything like that before (I had always had very regular periods my entire life) I kind of freaked out. I went to a gynecologist who referred me for an ultrasound. The only thing they could figure out was that I had a large fibroid (common--about 1 in 4 women have them) that was presumably interfering with the lining of my uterus, causing the premenstrual spotting. The doctor wasn't particularly concerned and said there really wasn't anything to do about it--unless I wanted a hysterectomy! So, now I just have to deal with several days of spotting each month, in addition to my period--kind of a bother, but not really a big deal. Thankfully, it didn't affect my ability to conceive. I now have a beautiful 7 month old baby girl. Maybe that is of help???