Here is some info on the procedure that you will likely need at your stage of pregnancy and the costs (having had a shifty round the web, it does seem that the .N.H.S will not cover you and you will have to pay privately):
from
www.Channel4.Com/health
surgical dilatation and evacuation (d&e) (from about 15 weeks of pregnancy). The cervix is dilated and the pregnancy removed in fragments using a suction tube and forceps. This usually needs a general anaesthetic. You may be able to go home the same day if you are healthy and the pregnancy is less than 18 weeks.
Abortion after 20 weeks is uncommon and will involve one of the following two procedures. You will need to spend one or two nights in hospital.
Surgical two-stage abortion (from 20 to 24 weeks). A surgical two-stage abortion involves two procedures performed under general anaesthetic: firstly the cutting of the umbilical cord and a second procedure to remove the contents of the womb.
Medical induction (from 20 to 24 weeks). During a medical induction the fetal heart is stopped and drugs are used to induce premature labour.
Current costs start from around £350 (or £405 in london) but go up to £750 plus in the later stages of pregnancy.