Yes, you can. There is a legal presumption that if a child is born during a marriage and the husband is not impotent or sterile, that child is the husband's child. Here, however, you have been separated for a good deal of time (making your child's birth, arguably, NOT "during the marriage") and it sounds like you will not have an issue with your soon-to-be ex-husband.
Why are you not divorced? I don't understand how you can bring a child into this world when you haven't even taken care of your relationship status. The question should be, how so I get a divorce decree from my husband in the fastest way possible.
Please RUN to a divorce attorney and get this taken care of. You would think that if your boyfriend is willing to make babies with you, that he ought to help you get a divorce. You owe your child nothing less.
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