that can be a sign or pre eclampsia - both of them are common signs of it - you really really need to get straight back to a dr and find out what's going on. not to be a drama queen or anything but it can kill you both. it's serious.
I think you need to realise it can also mean nothing, it depends on the levels of protein and how high you blood pressure is. I think if your midwife/Doctor was worried that much they would have taken further action. I would however do as confused mum said and get back in touch with the doctor xxx