I found a lump in my breasts

During sex last night I was rubbing all over my breasts and I felt something weird on the right one. It felt like a lump. I've never felt it before. I didn't say anything. When we finished I kept touching my right breasts to compare to the left one. The left felt normal. To my surprise I didn't panick I'm actually calm and just more concerned as I'm only 26. I got on Google to do some research in which it said it could be a lump or a cyst. It's pretty small. I woke up this morning and did another self exam. Still felt a lump. I'm going to make a same day appointment with my doctor on Monday when their practice is open. I'm keeping it to myself until I know for sure what is going on. I figured I post here and maybe get some advice until i can see my doctor. As I don't want to concern my family and friends. I think I'm more surprised at my reaction because usually when something is wrong I tend to freak out just a little bit. Update #1: Thanks for all the responses. The doctor ordered an ultrasound and i have yet to know when that is. I should be receiving something in the mail within the next couple days