she was sick; nausea; headache; diarrhea; experienced eight menstrual cycles after getting vaccination; throwing up with menstrual cycle; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. The reporter is the parent.  A 12 year-old female patient received bnt162b2 (BNT162B2), administration date 12Aug2021 (Lot number: EW0179) at the age of 12 years as dose 2, single for covid-19 immunisation. Relevant medical history included: "ADHD" (ongoing), notes: From Unspecified To Ongoing, For Other Conditions: diagnosed since she was 4 years old.; "to help sleep" (ongoing), notes: Patient taking Concomitant Products Melatonin to help sleep. Concomitant medication(s) included: ADDERALL taken for attention deficit hyperactivity disorder (ongoing); MELATONIN taken for sleep disorder. Vaccination history included: Bnt162b2 (DOSE 1, SINGLE, Lot: FW0198, Injection in right upper arm.), administration date: 22Jul2021, when the patient was 12 years old, for COVID-19 immunization. The following information was reported: NAUSEA (non-serious) with onset 2021, outcome "unknown", described as "nausea"; HEADACHE (non-serious) with onset 2021, outcome "unknown", described as "headache"; DIARRHOEA (non-serious) with onset 2021, outcome "unknown", described as "diarrhea"; MENSTRUAL DISORDER (non-serious) with onset 2021, outcome "unknown", described as "experienced eight menstrual cycles after getting vaccination"; VOMITING (non-serious) with onset 2021, outcome "unknown", described as "throwing up with menstrual cycle"; ILLNESS (non-serious), outcome "unknown", described as "she was sick". Therapeutic measures were not taken as a result of nausea, headache, diarrhoea, menstrual disorder, vomiting, illness.  Additional Information: Caller reported patient experienced eight menstrual cycles after getting vaccination, headache, diarrhea and nausea. Caller wants to know if these are reported side effects associated with the vaccine. Reporter was calling about the Pfizer covid vaccine. Reporter reported that she took the first dose on 22Jul2021 and after she took it, her first menstrual cycle after the vaccine, she started having diarrhea and throwing up. She also had the same symptoms with her menstrual cycle after the second dose. Then yesterday she was sick, had diarrhea and was throwing up. Last night when she went to bed, the alarm went off that her daughter was about to start her menstrual cycle since the mother has an alarm set of when her daughter has her menstrual cycle and she just started correlating this. States it seems coincidental. For her last three menstrual cycles since the first dose of the vaccine she get diarrhea and is throwing up. Prior to getting the vaccine her daughter has never had any problems with her menstrual cycle, she is always light one day, then a little heavier then a little heavier then its over. She was asking if anyone has reported anything like that before, if it has been reported as a side effect of the vaccine. She has had 8 periods prior to the vaccine and did not have this issue. Reporter reported about Her first menstrual cycle after the vaccine, she missed school because of it. She will call to the school to try and get the dates. She cannot recall the date of her menstrual cycles when this occurred. Treatment was reported as declines any. Outcome reported as the diarrhea lasts two days and throwing up only lasts about one day during her menstrual cycle.   No follow-up attempts are possible. No further information is expected.