Happy to know that you are okay. All's well that ends well... :)
Since you have a close history of breast cancer in the family, I would like to give you a little advice...Every month,one week or so after you finish your periods,try to remember to do a BSE (breast self- examination),If you see or feel something that is concerning you,go see your doctor for a check-up.A clinical breast examination by a health care professional should be performed at least every three years after age 20.
If you don't know how to do a BSE,I've copied a link so you will learn more how it is done.
http://breastcancer.about.com/od/risk/tp/bse_illustrated.htm
Being vigilant,even at your young age,will always benefit you.
Take care...and God bless.
Thanks ladies for your responses. :) After about 2 days the redness started to go away and since then it's nearly completely gone. I'm not too worried anymore about it.
To put your mind at ease, go to your GYNE.
The skin on the breast is the same as skin on any other part of the body and subject to the same problems. If this looks like a pimple then it probably is one. Since it appeared overnight then I doubt it has anything to do with breast cancer. You might try treating it just as you would if it were on another part of your body. If you are terribly concerned and this doesn't go away in a few days or a week then you could see a Dermatologist OR even your Primary Care Physican for some advice. Take care .....
It sound like a pimple to me, but it's really hard to say what it could really be. Pimples can happen on the breast like on any other part on the body.
Keep it clean and apply warm compresses on it and see how it goes.
If it doesn't get better in a few days,I would advise you to see your family doctor for a breast exam,if the little bump you have is indeed a pimple,the doctor might lance it and drain it.
Since you have a family history of breast cancer it's important that you be always vigilant about any changes in your breasts and seek medical attention.
Best wishes...