Expecting Parents Advice

Hello , we are expecting a child very soon and I’m trying to work out UC help , we are in council property and I’ll be going onto maternity soon and partner earns £1800 a month after tax , I will not be returning to work after until baby is 2 as uncomfortable leaving them in child care so quickly , but will be going back to work when child’s around 2-3ish , I was wondering what support we would get with UC top up as I pay myself around £1200 for all bills , and partner used to send me around £400 for bills as the place is in my name so don’t expect the full half , as he will be taking over bills and works away so has his own expensive outgoings , I’m wondering how much exactly I’d be entitled to with maternity pay and after it finishes ? Thank you