As Mochyn posted in this topic on 9th April :-
You are a British citizen and you claiming benefits will have NO effect on his claim for ILR
Not only that, your husband's visa says "No recourse to Public Funds", but do not think that every possible benefit is within the definition of Public Funds, as in para 6 of the Immigration Rules. In particular that definition includes nothing that is maternity-related.
So absolutely no problem your claiming Maternity Benefit, or indeed any other benefit you are entitled to, such as HiPG ..... Health in Pregnancy Grant.
By the way, the Tax Credits claim, please confirm that is in the joint names of you and your husband.