I noticed lately that, around the time of my cycle, my breasts have been getting really firm and tender, and they are actually getting bigger! I was a "late bloomer" compared to the rest of my family, but i'm 21 years old, should this be happening?
This isnt all that big of a deal to me, I was just curious.

Yes, it's quite normal for your breasts to feel firmer, fuller and tender when you're due on.