Avgas,
You got some really good advice there, go with that!
I will add that I blew airspace vertically a couple of months back while doing stall testing in a Navajo. Flight service called me during a dive test, which followed the flight test to tell me that I had. I was busy flying just then, so I did not pay attention.
The next day, I got thinking, so I phoned TC, and explained the whole thing. It would not make anyone happy, if the opening move from TC was to contact my client to ask who was flying his plane that day!
TC took all my information, and my explanation of paying attention elsewhere to keep the test safe and valid, and the mitigating things I had done (put the mode C on so others could see me on TCAS).
A few days later, I got an email saying that no action would be taken, and that was that.
I have never regretted being honest with TC enforcement types, in my few dealing with them....
Don't worry....