It's included in my prenatal vitamins so I'll be taking it the entire time. It's super important in the beginning but won't hurt if you keep taking it the whole time. It helps with neural tube/brain development and baby's brain keeps growing a lot even later in pregnancy so it won't be bad for you you can stop after 12 weeks if you want.
There's enough in your pnv that you shouldn't need to take an additional pill unless it's fir a medical reason. I'm epileptic so I take 8x the recommended amt for a normal person.