do lumps normally "break down" when you squeeze them?

Hi everyone. I am 23 years old with no family history of breast cancer. I found a lump on my right breast just right under my nipple about 1 month ago. I didn't give it much thought when I first found it as it was small and I forgot about it until a week ago I found it again. This time it is larger and very obvious. It is about 2cm when I pinch the lump and measure the width of my finger with a ruler. I have booked an appointment with my GP on Friday but I just got tested positive for covid so I couldn't go now. I have been monitoring the lump ever since I noticed it. Today I decided to try and squeeze it. It broke down a bit and I could feel the lump separated into 2 (still connected but I could feel they are moving away from each other). Do cancerous cells act like this? my lump is not too round but it is mobile - i can move it to the side of my nipple but it will return to its original position.