Just to add my two cents (as I am ttc right now and have MS). You should go off all medications when trying to conceive. But there are no documented cases of any problems from women who got pregnant and were on their meds (just didn't know yet). Obviously if you are trying to have a baby, you want to make sure there is no chance of anything effecting the development of your baby. But, the 6 month thing I am not sure about. I started TTC the same month I stopped my meds (avonex). My dr. Who is one of the top ranked neuros in the country said that if I didn't conceive right away there is always the consideration of taking the meds on the two weeks out of my cycle that I know I am not pregnant. Now every dr. is different and they all will give you different advice. I would listen to your dr. That is what they are there for. But none of the medications stay in your system 6 months, that I am sure is way too long. No offense to anyone else who responded but your Dr. is the only one who can tell you what is the best route for you to take. Not people on a website!

Good luck!