A deficient luteal phase is a very difficult thing to diagnose and it is even more difficult to prove whether it is happening every month. A blood sample (or several) for progesterone may be helpful whilst you are spotting. It seems reasonable to say that you are less likely to conceive if your endometrium (womb lining) is bleeding at the time that implantation would normally take place. Strictly speaking, you should try for 12 months before you can say you have a fertility problem, but I think nine months is a long enough time to try under these circumstances and I’m sure a fertility specialist would prescribe clomiphene to see if this prevents premenstrual spotting and helps you to conceive.