This site has some different medications, vitamins and herbal supplements that can be helpful while ttc. It clearly lists the amount and when it should be taken and what each different med/supplement will help.
http://www.tryingtoconceive.com/howto.htm
I have been taking 100mg B6 and a baby aspirin along with my prenatal everyday since cd2 so hopefully it will make a difference for me. I may try vitex next cycle if I don't get pregnant this time or if I lose this one.