period was 2/3 weeks late; huge blood clots; swollen lumps in my breasts; swollen lumps in my breasts; extreanlt tired; first dose on 04sep2021/second dose on 10dec2021; this is a spontaneous report received from a contactable reporter (consumer or other non hcp) from the regulatory agency. regulatory number: gb-mhra-webcovid-202202161424158790-cedco (ra). other case identifier: gb-mhra-adr 26610066 (ra). a 30-year-old female patient (not pregnant) received bnt162b2 (comirnaty), administration date 10dec2021 (batch/lot number: unknown) at the age of 30 years as dose 2, single for covid-19 immunization. relevant medical history included: "suspected covid-19" (unspecified if ongoing), notes: unsure when symptoms started, unsure when symptoms stopped. the patient's last menstrual period (lmp) date was on 09feb2022. the patient's concomitant medications were not reported. vaccination history included: comirnaty (dose 1, single), administration date: 04sep2021 for covid-19 immunization, reactions: "late period". patient was not breastfeeding at the time of period. patient was not enrolled in a clinical trail. the following information was reported: menstruation delayed (medically significant), outcome "unknown", described as "period was 2/3 weeks late"; thrombosis (medically significant), outcome "unknown", described as "huge blood clots"; breast swelling (medically significant), breast mass (medically significant), outcome "unknown" and all described as "swollen lumps in my breasts"; fatigue (medically significant), outcome "unknown", described as "extreanlt tired" and inappropriate schedule of product administration (non-serious) with onset 10dec2021, outcome "unknown", described as "first dose on 04sep2021/second dose on 10dec2021". the patient underwent the following laboratory tests and procedures: sars-cov-2 test: negative, notes: no - negative covid-19 test; positive. this report doesn't relate to possible inflammation of the heart (myocarditis or pericarditis). no follow-up attempts are possible; information about lot/batch number cannot be obtained. no further information is expected