Breast lingering soreness in the “back” of left breast, any cause for concern or is it ovulation related?

See your doctor and get scheduled for a mammogram.  It may be nothing but better safe than sorry

What did your gynecologist say when you brought this very important question to his or her attention?  This would be something to address with your doctor.  Random people over the internet cannot determine what (if anything) is going on with your breasts.  A mammogram, CT scan or sonogram might be in order but only your physician will be able to determine this.