If you and your husband cannot agree on custody of you child or children, the courts decide custody based on "the best interests of the child." Determining the child’s best interests involves many factors, no one of which is the most important factor.
This can be a confusing process. In spite, many parents are able to agree on custody. Nonetheless, the cases we handle involve narcissistic husbands who may not agree with anything no matter what.
Kudos to you if you and your husband agree upon custody. However, you will need to consult with an experienced custody lawyer to learn your rights if your husband obstructs the custody process.