Should I take the minimum 12 units this quarter or should I take 16 units?

I'm wondering if I should take an extra class this quarter. If I do, I won't have enough classes to fill up my spring quarter to maintain my full time student status (I already wrote down my 4 year plan of what I'm supposed to take EVEY quarter). Though I would like to take the class now to get ahead... But then I wont' have any class to take spring quarter that counts towards my major or GE requirements... The class would be just for fun I guess? By bebeeange...