You can go ahead with another shot of the rabies vaccine. There is as such no risk for rabies in the intermittent period.
When you write "last Rabies shot", why were you vaccinated in the first place? Since the vaccine is a series of 5 shots, I hope you weren't just given one shot--you should have received 5 over the period of a month (it's actually a very specific schedule).
Once you have received the rabies series, you should need any more shots unless you have another potential exposure with the virus--then I think it's 2 booster shots, given one and then another one two days later (though I would check to confirm this).
There's no need to get a rabies shot just to get a rabies shot....If you had the full series of shots, you're protected--then it's just two booster shots if you're exposed again.