Change the regulator yesterday, if not sooner.
No fuel should leak out, the diaphragm inside is split, this is why it is acting funny and overfuelling.
There is a diaphragm inside one side of which is open to the inlet manifold pressure via the vacuum pipe, the other side of the diaphragm is a valve that raises/lowers in a orifice to alter the pressure, so when you put your foot down and vacuum depletes the fuel pressure goes up, when crusing along on a light throttle with high vacuum the reg goes thr other way and lowers fuel pressure to it's base setting so you get a weaker mixture saving petrol.
tabetha