After removing IUD I was drinking pre natal vitamins , after 2 weeks I was seek (vomiting ) I stopped and everything was OK, after 4 month of trying to get pregnant I start drink multivitamin ( one a day women) and after 10 days I have same feeling... vomiting,
What could be a reason?

Be sure you take them with a full meal as that can sometimes help. I know some women who take 2 Flintstone vitamins, for example, instead because they just don't do well on prenatals or regular multivitamins.

Thank I am raking with a full meals

Try a children's vitamin. The main thing you are looking for prior to conceiving is the folic acid... 400mcg is what is recommended. You will find that in several of the children's vitamins and they may be easier on your system.

The prenatals usually have a good deal of iron in them and it can bother some people. Once you do become pregnant, you might ask your doctor about taking it in liquid form as that may help or even better, getting it from your diet if the supplements continue to bother you.