You don't mention your age, where these pimples are located or when your last mammo was. Have you done a thorough self exam of your breasts? Do you only experience this pain when your husband presses or squeezes your breast?
My advice, since this has been going on for a "few months," is to make an appointment with your PCP or gyno for a full breast exam including a mammogram. I don't mean this to alarm you........there are many reasons you could be feeling this discomfort, but only a doctor is going to be able to diagnose you conclusively. I hope you'll let us know what the doctor says and we wish you the very best.
RubyWitch