The same thing happened to me as well when I was pregnant. I stopped taking my pre-natals for about a week because they made me horribly sick. That is until a girlfriend of mine gave me the suggestion that I too take them at night and miraculously it worked. I was out like a log and slept through the icky feeling that it gave me.
~*Children are not a guarentee, they're a blessing*~
*~My lil bambino~*