I Hav Been Taking Atenolol 50mg One Per Day For

I hav been taking Atenolol 50mg one per day for the last 7 years .. I have been having pain over my left breast going on for 4 or 5 months & I have realized that this starts after a couple hours after I take this pill .. I'm a 64 year old man .. I have talked to my doctor about this & he just checks my blood pressure & always it's ok .. But this is becoming a containing thing everyday .. I live in Newfoundland Canada .. Just wondering if this has anything to do with this pill .. Would really apparat some advice .. Thank you Kindly .. Eric .