Felt a pain on her armpit, the same one, her right arm as she had the shot; Sees a bulge on her right armpit; could barely put her arm all of the way down because of the bulge; Couldn't Sleep; Feeling Tired and Lethargic; Arm was sore; Feeling Tired and Lethargic; This is a spontaneous report from a contactable pharmacist (patient). A 52-year-old female patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Solution for injection, Batch/Lot Number: EW0169), via an unspecified route of administration, administered in Arm Right on 25Apr2021 (at the age of 52-year-old) as DOSE 1, SINGLE for covid-19 immunisation. Medical history included ongoing PVC, ongoing abdominal discomfort, covid-19 from Dec2020 to an unknown date (after she got Covid in December, she had an accelerated heartrate from time to time), heart rate increased (after she got Covid in December, she had an accelerated heartrate from time to time). Concomitant medication(s) included metoprolol succinate 25 mg once a day (TOPROL) taken for PVCs from an unspecified start date and ongoing, multivitamin taken for an unspecified indication from an unspecified start date and ongoing; omeprazole (PROTONIX) taken for abdominal discomfort from an unspecified start date and ongoing. Caller stated since yesterday, so 2 days after the vaccine (on 27Apr2021), she felt a pain on her armpit, the same one on which she had the shot. Caller stated the pain was on her right arm pit and she saw a bulge on her armpit. Caller stated she was calling to see if maybe it was her nodules because she was having an immune response. Caller stated yesterday she could barely put her arm all of the way down because of the bulge and there was still a bulge there. Clarified she was still feeling the bulge and discomfort. Caller stated she works from home, and she did not work on Monday (26Apr2021) because she was feeling tired and lethargic, and her arm was sore, and she could not sleep that night, so she called in at work. Stated she was okay yesterday (27Ap2021) and she started working and she noticed that it was uncomfortable on her armpit, she touched it and felt a bump and she tried to go deeper to see if it was her nodules or what, but it hurt, and she could barely put her arm all the way down closer to her armpit. Stated she said she would take some Tylenol. Stated she had read they do not suggest females to go have mammogram until 2-3 weeks after their Covid shot because some females in that situation get a wrong reading or they are worried about possible nodules linked with needing more research to see if there is cancer involved but it is due to the shot. Stated she was like okay, but that wasn't her case because she had her mammogram over 2 months ago. She said she does not know if it will be like gone in another 24 hours and what can she do. She wanted to know if other people reported the same thing as to know if it was something she should worry about or not worry about. Stated the blood filters infections and she wanted to know if it was okay and when she should worry. Patient received treatment as Tylenol 500mg PRN, does not take it every 4-6 hours, takes 2 a day. The outcome of events Armpit pain and sees a bulge on her armpit was not recovered, Arm discomfort, Pain in arm was recovering, Feeling Tired and Lethargic was recovered on 27Apr2021, Sleep disorder recovered on 26Apr2021.  Follow up attempts are completed. No further information is expected.