With low mileage vehicles, especially when driving very short trips (<10min) the biggest concern is with the engine. Here is why:
During a cold start, the cold piston rings, seals etc. have shrunk allowing fuel and water vapor to enter the crankcase causing dilution of the engine oil. This in turn will reduce the lubricating properties of the oil. Normally this fuel and water evaporates when the vehicle full warms up and is driven a decent distance (This can easily take 20min at highway speeds).
The solution for vehicles driven on short trips is to drive longer distances (1 hour?) at least once per week and change the oil more frequently. Schedule 1 recommends every 3750mi (6000km) or 3 months, whichever occurs first.
Seeing you are already at the 3 month mark, it's time for an oil change even though you are way under mileage wise. Also, don't bother with synthetic oil. The benefits are reduced somewhat by the fact you are changing at such low mileage.
If you really want to monitor your engine wear and ensure your engine oil is in good health, I strongly recommend oil analysis. There are several labs, but here are the ones I know/heard of:
http://www.wearcheck.com - Locations in US and Canadahttp://
www.blackstone-labs.com - Located in the US, offers free sample bottles/kits