Did I claim to many on my w4?

I just started my first job and filled out a W4. I am married with 2 children that can be claimed. I was afraid to over do the exemptions so I claimed 3, should I claim 4 (myself, husband 2 kids) or leave it alone? I do not need a return at the end of the year I would rather break even and make more per week. We dont make a lot of money so I should receive the earned income tax credit and stuff like that. Also how many should I claim on the state tax paper? I live in West Virginia. Thank you