Decided to go on a low dosage of zoloft (sertraline) to help with depression. any bad side effects i should be concerned with? i am otherwise healthy.

Unlikely: no bad ones on low dose. The most common ones are activation, fatigue, stomach upset, decreased sexual drive. All should be low grade at low dose if at all.

You'll know: Watch yourself and note any unusual reactions. Just keep track for a week and perhaps verify with someone close to you who might notice things. You may have none, or briefly some - Some have bad ones, but you'll find out soon. If you need to stop, let the Dr know ASAP and they'll taper you off.