Nipple soreness and lump

I am 33 and i never had any problems with my health.  I run 3-5 times a week and stay on healty diet.  
Over night, i woke up with a nipple sorenss on my left breast.  Just on the left breast, when i touch the nipple, it feels extremely sore like i have a bruise.  And it feels like i have something that is swollen inside my breast.  It feels like a lump right behind my nipple and the entire left breast seems to feel tight with soreness sensation.  I don't have any discharge, i am on a birth control (for about 12 years-never had a problem) and i just finished my period (about a week ago). So it's not hormonal and i didn't do anything abnormal. Should i be worried?

KDL

[Cleveland Clinic]

Dear KDL, Over the internet without ability to evaluate it is difficult to advise.  If this is a change, continues to be a problem and of concern it is best to have it checked by your doctor.  

[carolee407]

no, not worried, because most of the time that kind of thing is a benign cyst or other benign condition.  but you should have it checked out now anyway, to rule out anything more serious and so that you can stop wondering/worrying about what it is.