2001 Mazda Protege What's Leaking??

I drove my car home from work a week ago, and I parked in the garage as usual. I went to my car about 30 minutes later to find a pool, of what looked like oil, on the drivers side. I felt the unknown fluid and it didn't feel like oil. 10 to 15 minutes later the fluid had desolved or evaporated. My oil light hasn't come on and my car hasn't been running hot that I can tell. About 6 months ago, I had the radiator replaced, as it had a crack. And I change the oil every 3 months for preventive reasons. Any one have advice to share? Really not looking to purchase a new car at this time! HELP!!