So i was on my first checkride for my PPL. I had failed the slip to a landing so i was already going to have to retest. Everything else i had passed. As we approached my home airport, i was given pattern entry instructions. I entered on base as usual, and turned final. Realizing i had not been cleared to land, i radioed the tower and asked for clearance, assuming they just forgot since the airport was super busy. They didn't respond, as it was extremely busy. I radioed again, no response. I asked my DPE what i should do, as we were already on very short final. He told me just to go ahead and land. As the wheels touched, tower called for another aircraft to go around. I was handed over to ground as normal and parked, never given a number to call or anything. This was back towards the end of november. A week later, i passed my checkride, neither me nor my DPE thinking anything of the incident. Today, my old instructor called and stated that the rental company recieved a letter from the FAA about an incident on that day, and i was the only one who had flown the plane all day. Whats gonna happen with the FAA? Im terrified.