Does it look like it's coming from the back (closest to the firewall) or the front (closest to the radiator) of the motor? Does it drip oil on the ground if you start it up and leave it running while you're parked? I had a similar problem not too long ago after putting my motor back together and...
Take the time to pull the pan and remove it. It's cheap insurance that you will never have any problems with it later, personally i've found that (Murphy's law haha) "if it can go wrong, it will." I just figured i'd give my 2 cents! Good luck!