Was the RTF rather busy at the time? Could it be that the calls to yourself were saturated out by other pilots transmitting too? I'm also unfamiliar with the FAA and how they would progress this, but in the UK there wouldn't be any action against you as such, but just an education alerting you to what the situation was. Over here the frequencies can be disected enough to work out if more than one person was talking at once and if the transmissions to yourself were "stepped on". Put it down to learning, hopefully it will stay that way, it happens everywhere in the world so don't worry too much about it.