The Royal College of Obstetricians & Gynaecology have produced this leader about the vaccine and pregnancy
The basics state that the COVID-19 vaccines have not yet been tested specifically in pregnant women in the UK but tests in the US have not shown any concern. The vaccine being used is not live and so can’t infect you or your baby, though you may feel some side effects just like anyone else if you do choose to take it.
It seems very much like you need to weigh up the risks of catching Covid19 in late pregnancy which can cause issues compared with the vaccine. I would suggest asking yourself questions such as:
Do you feel at risk?
Are you staying home and very much still isolating yourself? Or are you out and about and in contact with different people daily?
What’s the local infection rate in your area? You can put your postcode into this website for local info: https://coronavirus.data.gov.uk/
I would also suggest having a good chat with your midwife, she may know a bit more, definitely have local info she can share with you and she may be able to put you in touch with other pregnant mums in your area you can chat with about this too.