did not have a period in May or Jun or most of Jul; had spotting until the 3rd of Aug when it became incredibly heavy; I am still having it now and it heavier than after i gave birth/I'm soaking a heavy flow pad every 45 minutes; it's painful and heavy enough that I'm worried about it because this is longer and heavier; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 43 year-old female patient received bnt162b2 (BNT162B2), administered in arm left, administration date 17May2021 (Lot number: EW0185) at the age of 43 years as dose 2, single for covid-19 immunisation. The patient's relevant medical history was not reported. There were no concomitant medications. Vaccination history included: Bnt162b2 (lot number=Er8736, solution for injection, administration time=03:45 PM,, dose number=1,, vaccine location=Left arm, ), administration date: 26Apr2021, when the patient was 43 years old, for COVID-19 immunization, reaction(s): "I should have gotten my period around the 5th of May and I did not". The following information was reported: MENSTRUATION DELAYED (non-serious) with onset 28Jul2021 12:00, outcome "not recovered", described as "did not have a period in May or Jun or most of Jul"; INTERMENSTRUAL BLEEDING (non-serious) with onset 28Jul2021 12:00, outcome "not recovered", described as "had spotting until the 3rd of Aug when it became incredibly heavy"; HEAVY MENSTRUAL BLEEDING (non-serious) with onset 28Jul2021 12:00, outcome "not recovered", described as "I am still having it now and it heavier than after i gave birth/I'm soaking a heavy flow pad every 45 minutes"; DYSMENORRHOEA (non-serious) with onset 28Jul2021 12:00, outcome "not recovered", described as "it's painful and heavy enough that I'm worried about it because this is longer and heavier". The events "did not have a period in may or jun or most of jul", "had spotting until the 3rd of aug when it became incredibly heavy", "i am still having it now and it heavier than after i gave birth/i'm soaking a heavy flow pad every 45 minutes" and "it's painful and heavy enough that i'm worried about it because this is longer and heavier" were evaluated at the physician office visit. It was unknown if therapeutic measures were taken as a result of menstruation delayed, intermenstrual bleeding, heavy menstrual bleeding, dysmenorrhoea.  Additional Information: The patient did not receive any other vaccines within four weeks prior to the vaccination. The patient did not receive any other medications within 2 weeks of vaccination. Prior to the vaccination, the patient was not diagnosed with COVID-19. Since the vaccination, the patient had not been tested for COVID-19. The patient has no known reported allergies. Patient received second dose on 17May2021. Patient then did not have a period in May or Jun or most of Jul. (Patient extremely regular and always have my periods around the 5th of each month) Finally patient got my period on the 27Jul2021 and had spotting until the 03Aug2021 when it became incredibly heavy. Patient still having it now and it heavier than after I gave birth. It is painful and heavy enough that patient worried about it because this is longer and heavier than patient have ever had before. Patient periods normally only last 6 days with the first three being semi heavy. This is not normal at all. It shows no sign of stopping but it is so heavy that I am soaking a heavy flow pad every 45 minutes around the clock and that's never happened to me before.  No follow-up attempts are possible. No further information is expected.