I say all the time on here I think shared leave should be the norm.
Yes it sucks to go back to work a month earlier than you would otherwise.
But (if you have a decent partner) the benefits outweigh the negatives-
You will not be the default parent. Your husband won't be one of those dads who is great at playing with the baby but has no clue what their routine is, when they go for naps, how to settle them, what to feed them, how to pack a bag for a day out. You only need to read mumsnet to see how common this is - partly down to shit men, but some of it is they have never had the responsibility of doing all this on their own before.
The baby will settle equally for you, or him and this is likely to continue as they get older. It's not that common for a child who's fallen over to want their mum or their dad equally
You both understand each others perspectives a lot more eg understand the real impact of the worker just popping out for a few drinks after work
He will do the settling in at nursery while you settle back into work. Both of those things are stressful and can be upsetting and you only have to focus on one of them.
Men who take a share of the parental leave spend a lot more time alone with the baby and are studies have shown they are much more likely to be equal parents eg do more of the mental load and chores are split more equally
By all means say no, but be aware you will more likely be one of the majority who's 'husband forgets to put suncream on the baby' or similar, or can't go out because your toddler will only settle for you
I'd caution this all only works if your husband is a decent human. And not supporting you through pregnancy and not talking to you and slamming doors is NOT a good sign
Shared leave is also complicated as it's more difficult for you to tack on holiday to the end (as his has to be taken before the 12 months is up). Depending on when your annual leave year is, and when your mat leave is due to start this can be a pain. An alternative is, if you can afford it, he takes a month of leave (I think it's parental leave, the one that can be taken unpaid in blocks til your child is 18) after your mat leave has finished. It's pretty much the same thing trom his point of view but means you don't need to cut your leave short