If your essay is only 3000 characters and you feel like you're finished I wouldn't sweat it. The length differs for everyone.
My essay is on the longer side, just slightly over 4300 characters. I did have quite a bit to mention though-- parent with an illness, pharmacy technician experience (over a year), hundreds of hours of volunteering experience: 5 years of administrative experience in a free clinic for un/underinsured patients staffed primarily by volunteers, hands on direct patient care experience in a hospital setting, and being a tutor in my community.
There was some other stuff I could have mentioned, but I only chose to mention experiences that had a profound impact on my life and/or directly influenced my decision to pursue a career in pharmacy. If you feel yours is finished, don't clutter it up with junk just to make it longer. The quality of your personal statement is far more important than the length.