Well, my baby will probably figure it out on her own!
I meant that I could relate to your situation because my baby was conceived with donor sperm, so like your husband, I have no biological relationship to her. My partner is her biological mother.
For us I suppose it is easy, in that we couldn't hide the truth if we wanted to. But we have planned to always talk about it. I thought it might feel strange or alienating, but it really doesn't. There is nothing that could make me feel less my baby's mother. I am the person who could get her to sleep as a newborn; I'm the person she snuggles up against when she has a cold and won't settle. There's just no way I wouldn't recognise her as my daughter or she wouldn't know me as her mother.
Talking to friends who have adult children through adoption or IVF or other 'non-biological' means, the story is the same. I really think you mustn't worry. You may want to think a lot about how you will choose to approach the topic, and how you feel about it, but there is no concrete reason why a baby who isn't biologically yours, wouldn't feel like yours.