Irregular vaginal bleeding; Menstrual cramping; Horrible low back pain like back labor; chills; Injetion site swelling; Injection site pain; Headache; nausea; Spontaneously began bleeding/ got period; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient. Other Case identifier(s): 20211263070(0) (Mfr Control No.).  An adult female patient (not pregnant) received bnt162b2 (BNT162B2), administration date 24Mar2021 (Batch/Lot number: unknown) as dose 1 , single for covid-19 immunisation; janssen covid-19 vaccine (JANSSEN COVID-19 VACCINE), administration date 27Dec2021 11:00 (Lot number: 211D21A) as dose number unknown, single for immunisation. Relevant medical history included: "Perimenopausal" (ongoing). The patient's concomitant medications were not reported. The following information was reported: MENSTRUATION IRREGULAR (non-serious) with onset 27Dec2021, outcome "not recovered", described as "Spontaneously began bleeding/ got period"; VAGINAL HAEMORRHAGE (non-serious) with onset 28Dec2021, outcome "not recovered", described as "Irregular vaginal bleeding"; DYSMENORRHOEA (non-serious) with onset 28Dec2021, outcome "recovering", described as "Menstrual cramping"; BACK PAIN (non-serious) with onset 28Dec2021, outcome "recovering", described as "Horrible low back pain like back labor"; CHILLS (non-serious) with onset 28Dec2021, outcome "recovering", described as "chills"; VACCINATION SITE SWELLING (non-serious) with onset 28Dec2021, outcome "not recovered", described as "Injetion site swelling"; VACCINATION SITE PAIN (non-serious) with onset 28Dec2021, outcome "not recovered", described as "Injection site pain"; HEADACHE (non-serious) with onset 28Dec2021, outcome "recovering", described as "Headache"; NAUSEA (non-serious) with onset 28Dec2021, outcome "recovering", described as "nausea".  Additional information: The patient previously received BNT162 (Pfizer vaccine) (Dose number in series 1) on for Prophylactic vaccination, and experienced severe reaction (dose number in series 1) and did not complete the series. The outcome of severe reaction was not reported. On 27 Dec2021, after receiving the vaccine the patient spontaneously began to bleed and got her period, she stated it was a weird cycle not normal. On the patient had reactions of headache, nausea, swollen and painful injection site/arm and Chills. The patient added that she was also experiencing irregular vaginal bleeding during perimenopause, along with horrible low back pain like back labour, and reports that by 14: 00 on 28Dec2021 she had vaginal spotting which then turned into a very heavy flow, no clots, bright red, with menstruallike cramps. On the patient reported that she still had the heavy flow and the same symptoms, improving slightly except for the vaginal bleeding and injection site pain which she stated were the same he same (dose number in series 2). Causality Janssen covid-19 vaccine (covid-19 vaccine ad26.cov2. s) (suspension for injection) (covid-19 vaccine ad26.cov2.s): spontaneously began bleeding/ got period, irregular vaginal bleeding, menstrual cramping, horrible low back pain like (back pain back labour (low back pain), chills, swelling at injection site/arm, pain at injection site arm, headache, nausea:  causality as per reporter (drug/vaccine)  possible , causality as per mfr. (drug/vaccine) - possible.  No follow-up attempts are possible; information about lot/batch number cannot be obtained. No further information is expected.