vitamin information

My husband and I have been TTC for about a year, we had a miscarriage I August. Anyways, I've seen so many posts about people who have gotten pregnant after taking additional supplements: fetilaid, vitex, pregnancare conception, geritol... Etc. 
my question is if you already are taking a prenatal do these do anything more to help you conceive? Do you need additional supplements? If anyone can give me any insight it would be appreciated.