Did you guys apply for a spousal application? If you did when? Whats your timeline now?
I guess your best bet is to apply for a visit visa, Provide the embassy with proof that you are pregnant, and that you don't feel well emotionally and you need husband to be there with you, Maybe get some recommendation from doctor or a psychologist that you are very depressed and thats not good for your or baby's health and you really want your husband to be there. Pin all that with the visit visa application and apply while hoping for the best??
I've heard from my lawyer that some people get approved if they provide a solid enough reason especially in pregnancy