Can you ring labour ward instead of GP?
Yes, sypmtoms of Pre-Eclampsia are odaema (especially in hands and face, although when I had PE it was everywhere), flashing bright lights in your vision, headache, high BP, protein in your urine, unable to pass urine, and eventually fitting.
Are you passing urine OK? And does it seem normal? I.e. not concentrated?
If I were you, I'd ring the labour ward (so you can speak to a midwife, not a GP) explain about the odaema you have, mention any thing else you feel isn't quite right and they will decide what to do from there. Until then, stay sat down with your feet up. Don't stop drinking to try and stop the swelling, infact it is advised to drink more than usual.
Good luck, I am sure everything will be fine, swelling especailly in the legs is very common in pregnancy.