B.C.
I was told to keep taking them as long as I was breast feeding.
You can take them as long as you want to.
Some women like them even when they aren't pregnant/breast feeding/trying to conceive.
Ask your pediatrician and doctor and see what they say.
I tried a few prenatal vitamins before I found one that didn't upset my stomach so maybe you could try a different one that will work better for you.