Still leaking

I just replaced a rear main seal but also installed the crankshaft repair kit before doing so. The car did not have any leaks at all and I drove it for a few hours within a 2 day period, checking periodically for possible leaks. I parked it in the garage and put newpaper on the floor to make sure. 2 days went by and I took it out of the garage and there it was on the paper, oil. It wasn't a significant amount but it still concerned me, along with putting me in a really bad mood. I also bought a new set of valve cover gaskets because they were in need of replacement but I have only replaced the passenger side so far. They really didn't leak much but you can't see what's going on with the driver side seal unless you take the intake off(which I haven't just yet). Could it possibly be the valve cover gasket being that bad that it's leaking oil down the back of the engine, making it seem like it's the rear seal? If anyone has any input on this, I'd really appreciate it. thanks all.