boble - I have read that spotting after O and before AF can indicate low levels of progesterone (but someone please correct me if I'm wrong). This would also make it difficult for a embryo to stick since progesterone builds up the lining. It was a while ago now, but someone on this thread mentioned that they had bought Toni Weschler's book, Taking Charge of Your Fertility. Was it you? I have a copy too and I know she discusses pre-AF spotting in one of the appendices. But I don't believe it is normal. If I were in your situation I would demand some answers from my doc or find another one. "You're just wired that way" is not an answer and is, at best, very unprofessional. All the best hun.