I'm also pro choice. I don't know what OP should decide, only OP can weigh up the potential impact on herself and decide if that impact will have a detrimental affect on her relationships.
I keep pointing out the problems with the current set up won't go away if she has a termination because the finances don't make sense.
We don't know if DH actually works 5 days a week or not.
We don't know how much he actually earns.
We don't know how much of his salary he contributes to the joint account.
We don't know if he'll actually get a vasectomy.
We don't know if it's possible to return his expensive car early.
We do know OP has to have the house clean and tidy when he gets home from work.
We do know he pays his Mum £175 per month, which is over half what he is receiving from OP's parents.
We do know he signed up for a car payment of £300 per month despite not having the money for a deposit and then actually took the money OP's parents gave her as a gift to get a better car for herself to use as a deposit for a car for himself.
We know they live in a 4 bedroom house despite having either 1 or 2 children when that house was bought.
We don't know if he has other expensive things like an expensive phone on an expensive phone contract. I've asked but OP hasn't answered.
We don't know if OP is afraid of her DH.
We do know that he gets annoyed when she tries to discuss finances, and shuts down the conversation by saying it's not a competition as to whose parents give more or that he's not hiding hundreds of pounds from her.
OP doesn't know if he has £37000 per annum or £2100 per month.
He has threatened to divorce OP if she has this baby.
He has said he can't afford to divorce her (whatever that's supposed to mean - I'm thinking he thinks he's better off now rather than actually paying maintenance).
We don't know if he cares for the children or does any housework when he is at home.
It's a very strange marriage.