If you plug into a guitar amp, it won't sound much like a ukulele, but it could be a very cool sound. To capture the true acoustic sound of the instrument, you'd be better off going into a "hi fi" amplifier that gives you plenty of clean headroom. An acoustic guitar amp like an SWR California Blonde, Fishman Loudbox, or an AER would be ideal.
You might also think about going into a preamp like a D-TAR Equinox or even Mama Bear to remove the "artifacts" from the pickup and make it sound more like the acoustic sound of the instrument.
Best of luck.
- EAS