well it could mean you are pregnant because pregnancy hormones are what make your breasts do crazy things, but then again your hormones might just be acting crazy for no real reason. wait till ur period comes and if it doesnt take a test, but if ur too nervous and cant wait that long then take an early response 3 days before you expect your period to come.. also yes you can have symptoms 10 days after conception because it takes about 9 for the egg to implant.however it does seem rather soon for you to be having that particular symptom