Congratulations bugoven! :)
My pain relief for DD1 consisted of 2 paracetamol. 
I wanted G&A, but it didn't arrive until after she was born. And the MW sent it away again before realising I needed stitches...
I had Pethadine in the fridge just in case, but I never felt I needed it. Given that and what has been said here, I won't bother requesting it this time around. I only briefly had a moment where it felt like it might all be too much, and that must have been transition as DD arrived moments later.
Would recommend a water pool for anyone allowed it, but most of all staying as mobile through pregnancy as you can. Gravity is awesome, and moving around helps things progress as well. But most of all, positive thinking! Stay calm, you can do it. You come from a long line of women who successfully managed to have children - with or without assistance. :)
In terms of finances, employers are not allowed to deduct from statutory maternity payments (but can deduct from enhanced payments if you get any) and you are entitled to receive all the non-performance based benefits you usually do.
IIRC, Pension payments that you make won't go out but if your employer usually contributes then they have to continue to do so. Any private healthcare you have will continue (and it's worth checking whether you get any maternity cover via private medical, as some will pay for a private room in hospital or a non-emergency CS if medically required). Student loan payments are not taken, they go on hold.
If you receive childcare vouchers then you will continue to receive them throughout maternity. Due to this, for first timers it's worth assessing whether it's worth starting to collect vouchers before the child is born. It reduces your salary slightly for the 6 weeks at 90%, but unless you're earning huge amounts you gain more in vouchers for the maternity period. However be wary, as vouchers only last for a year.
Caveat that I'm not an expert - this is just my memory from last time!