Thanks all. Nurse finally called back and said risk was minimal in my circumstances so no need to rush to out of hours over the weekend but to get to GP on Monday. Saves me a few hours waiting around tmw, now just got to get past the dreaded doctor's receptionist to get an appointment on Monday morning!
You're better off going to a GUM clinic than your GP. They'll diagnose you while there and give you the treatment. You can get the cream to treat rather than the ABs if you want because the ABs are bloody awful but I don't know if it can be used during pregnancy.