Oil in my antifreeze?

[1Madmachinist]

I bought my first Porsche!!
A 2000 Boxster S with 88,700 miles at a decent price.
When I bought it everything worked perfectly. I checked all the fluid fills (no mayonnaise or weird smells) , crawled under the car in a hot parking lot (Oil blow-by on the left cylinder head no heavy drips just blow by), open and closed everything (everything worked as it should except the stock navigation system but it runs on DVD's so what are you gonna do), drove the **************** out of it for 20 minutes, and all seemed well. I've put around 500 miles on it since. The day I got it home the passenger side window regulator died which should be an easy fix. Tonight I was checking the oil and and water levels again and noticed there is what looks like oil in the antifreeze. The oil dipstick didn't show signs of antifreeze contamination but there's no way to know for sure without draining the oil. The temp gauge has never gone above half way no matter how hard I push it and I have pushed it pretty hard in relatively hot temps so I am hoping it hasn't blown a head gasket. Could this be the oil cooler O-rings?