You should check with the hospital where you will give birth. They may have specific policies in place that will mandate how the paternity will be cited on the birth certificate (BC).
Regardless of whose name is on the BC, your husband is the legal father of the child until the legal documents of your divorce state otherwise. You should engage a local attorney ASAP, to initiate your divorce. Although it cannot be finalized until the birth of your baby, you can get it started so that as soon as your child is born, you can finalize it. Then your boyfriend can file an acknowledgement of paternity. ( Your attorney may be able to combine these processes.)
This answer is general information which does not establish any attorney-client relationship between the person asking a question and the person answering, or a duty to respond to ongoing questions; nor is it intended to replace competent legal assistance in the jurisdiction where the matter/issue arises or is before a Court.