Switched prenatals, change in symptoms

7 weeks 4 days, I have been so miserably sick for almost 3 weeks. My prenatal was so big it made me throw up almost every time I took it, my doc had me switch to a chewable vitamin and I have felt so much better ever since. We've had 3 previous miscarriages and I'm scared it's happening again. Have any of your symptoms eased up because of a switch in vitamins?