It all depends on the person taking the Folic Acid as to how long it will take them to get pregnant but most people get pregnant 2 weeks after taking Folic Acid.
When you're trying to get pregnant it's important to take a daily supplement of 400 MG of the Folic Acid and continue taking the supplement of Folic Acid until you're 12 weeks into your pregnancy.
Men should also take some Folic Acid as it helps to increase a mans sperm count which increases the chances of getting a woman pregnant.