it is generally  advised to take all tablets after meals hope you are following that . if the tablet is big divide into 2 and take . drink lots of water after any medicine and do not lie immediately sit for at least 15 minutes. 

speak to your doc to give you some syrup if possible ?!

Yaa.. I too had that during my pregnancy. But tablets are very important for baby's growth. Especially folic acid and iron. Iron tablets will cause vomiting sensation. Please speak to your doctor once.