I too was in your situation, I took it from when I found out I was pg (4wks) but then just over two weeks later I got slaughtered by morning sickness. Never got back onto the folate tablets as I couldn't keep them down while I had M/S - it didn't go away until after 16wks pg.

I did get folate in the form of vegemite as on the occasion that I could keep something down, it was usually toast with vegemite.