Actually, since they add on two weeks to your gestational age there are actually considered to be 6 not 4 weeks in your first month and then 4 weeks in each month after. So you'll be more like 3 months and 1 week at your appointment...just a little confusing tid bit I thought you'd like to know.

Anyways, as far as vitamins go I take Nature Made Pre Natal Multivitamin and mineral supplement. You can pick anyone you want really just make sure it doesn't contain anything artificial, like colors or preservatives and that it has minerals and is high in iron and folic acid and contains all the vitamins you would need in a day. Something that helped me as far as the right amount of each vitamin/mineral and nutritional/dietary questions, I picked up this book:
Amazon.com: Pregnancy Do's and Don'ts: The Smart Woman's A-Z Pocket Companion for a Safe and Sound Pregnancy: Elisabeth Dr Aron: Books
As far as diet goes, limit caffeine (from ALL sources) to the equivalent of 3 regular size cups of coffee a day, try to eat plenty of fruits and vegetables and eat more frequent and smaller meals (this is said to help with vomiting/nausea but I'm not sure if it works for everyone). I also recommend reading:
Amazon.com: The BabyCenter Essential Guide to Pregnancy and Birth: Expert Advice and Real-World Wisdom from the Top Pregnancy and Parenting Resource: Linda J. Murray,Editors of BabyCenter,Jim Scott,Leah Hennen: Books
Good luck!
