Bump on left side of my breast?

Hey guys so I’m 23 yo. And I was laying down last night and felt a bump on the left side of my breast. It hurts a little when I touch it. It’s not red or anything but I have to touch it to feel it in there. I’m kinda freaking out. I already made a appointment for tomorrow but I can’t just keep calm. Idk. Anyone gone thru something like this? 😕