Ideally, you should take folic acid supplements for 3 months before you get pregnant and until you are at least 12 weeks along. This is when your baby’s spine is developing. But it isn’t harmful to take folic acid all the way through your pregnancy so you can carry on if you are taking pregnancy multivitamin tablets that contain it. Try not to worry if you haven't started taking folic acid yet and start taking it as soon as possible.