Clomid and Luteal Phase Length: Understanding the Connection

Question
I am 33 years old and I have 3 children.  My question is:  I have recently started using Clomid to assist me in conceiving, I have used it for 3 months now.  Before I started the Clomid I had a luteal phase that lasted 13 days, after I started the Clomid my luteal phase went to only 9 days. Is it possible that the Clomid is shortening my luteal phase? I thought Clomid was supposed to lengthen the luteal phase not shorten it.  

Answer
Clomid works by interfering with the negative feedback mechanism (in the hypothalamus) for FSH. Therefore, FSH (produced by the pituitary gland) continues to be produced and more follicles (in the ovary) are matured, thus increasing the chances of ovulation. Clomid does not affect the luteal phase of your cycle. That is under the control of progesterone. If you do not produce enough progesterone, you may have a short luteal phase. If your luteal phase has become shorter than usual, I would suggest that you get a progesterone level and, if it is below normal levels, take some progesterone supplementation to increase the luteal phase.