Can a knot form under the skin of your boob if bitten hard enough? I'm 27 and shouldn't have a knot here.
I guarantee you will not get any kind of good medical diagnosis over the Internet from random people. If the question is serious, it would definitely be worth going to the doctor to get checked out
You may want to check you doctor, I don't want to scare you but it could be cancer.
best get it checked by a doctor