What is this big lump on my ?!?

3 days ago I noticed I had a pea sized red bump on the om of my left cheek. It hurt when I sat down, when I got up from sitting, or touched it and put pressure. I didn't pay much attention to it because it looked just like a big pimple or mosquito bite. It was also hard. But, after 3 days I noticed it's different now. It's more a lump than a bump now and it's about the size of a dime. It's also very squishy and it doesn't hurt when I touch it anymore. Only when I sit down or stand up. I'm starting to worry now because it's gotten much bigger. Does anyone know what this is??! I'm going to be going to the doctor soon to check. I'm 15 years old. Answers please !!