This is a spontaneous report from a contactable consumer (the patient). A 44-year-old female patient received the second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, ER8729) via an unspecified route of administration, administered in Arm Right on 10Apr2021 09:30 at age of 44-year-old at single dose for COVID-19 immunisation. Medical history included ongoing endometriosis, allergy: penicillin and heavy periods pertains to her endometriosis. The patient had no concomitant medications (reported as "no other products"). The patient previously took the first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Lot number EN6203) via an unspecified route of administration in right arm on 14Mar2021 at 09:30, at age of 44-year-old for COVID-19 immunization, with the first dose everything was fine, she had a little fatigue, but all fine. The patient had some symptoms that were normal and subsided. Caller had a delay in her menstrual cycle after her second dose on 30Apr2021 and was still delayed. She took pregnancy tests to rule out pregnancy. She was not irregular, that's why she did the test. She had heavy periods, cycles every 25-28 days and heaviness pertains to her endometriosis. It abnormal for her and she was thinking on behalf of her 14 year old daughter. Caller asked if the vaccine affecting girls that are menstruating and would it affect their fertility or delay or affect them in the long term. Caller would normally go through her normal OBG/GYN, but was referred to call Pfizer. Caller asked if other women called with similar experience, she was trying to get alleviated that it was normal. She obviously didn't care, she had her 4 kids. She didn't want her daughter to be dealing with this down the line. Caller was 4 days late, but was still in the window to get it on time. Caller felt this is important to report. Caller may be a week or so late. She took an iron supplement. Caller had nothing after the 1st dose. On 13Apr2021, she had fatigue, low grade fever, nausea for 2-3 weeks after the second dose with lower back pain.  The nausea was a concern to caller because it didn't lift after a few days.  She had read about it through the CDC, but had no symptoms until 2 days after. Caller's low back pain was centralized, middle of back, like tailbone, and has not resurfaced. Her temperature was like 100 degrees and lasted 24-48 hours, not as long as back pain and nausea. Caller had fatigue with her endometriosis and issues.  She is still doing her normal routine, she was pretty fatigued that 2 weeks, and not like herself. Caller wanted to make sure and she got a pregnancy test, because the nausea hadn't lifted and the last time she felt that kind of sickness was with her pregnancy. The nausea stopped, but her period hasn't come. It was all the second dose. After the first dose, for 24-48 hours, she took it easy and monitored herself. She was lightheaded more with the whole 2 weeks and dizzy at times.  She was not eating as well, her appetite was suppressed and she feels is was all related. It was on and off, but caller didn't document the exact dates, but she recovered from all the symptoms for the most part. Caller didn't expect a lengthy call, she was seeing if she experienced normal side effects and wanting to know about her daughter. The events did not require a visit to emergency room. Nausea and back pain fatigue and lightheaded require a visit to physician office. The outcome of events "nausea", "lower back pain" was recovered on 27Apr2021, the outcome of event "low grade fever" was recovered on 15Apr2021, the outcome of event "delayed menstrual cycle" was not recovered, the outcome of event "severe fatigue" was recovered in Apr 2021, the outcome of other events was recovered on an unspecified date.