SSRIs for PMS?

Hello, I've recently gone off of the birth control pill and now have the copper IUD (it's been a few months and I really like it).  While my actual period is manageable I've found that I have worse PMS in terms of up and down moodiness.  In the past, my gyno has recommended an SSRI type of drug (Prozac, Paxil) to take just 7-10 days before my period.  I had an annual physical yesterday and my primary care doc who is also a woman recommended the same kind of treatment.  Does anyone currently use these or have tried them for PMS/PMDD?  Would love to hear both positive and negative comments or feedback.  Thanks!