Has not had any energy; it's hard to breath with no oxygen in her blood; it's hard to breath with no oxygen in her blood; Had been checked for anemia in Apr2021 and told she was anemic/ iron has been low; period still ongoing and strong, really heavy bleeding with clots; prolonged bleeding with periods; This is a spontaneous report from contactable consumer (patient). A 43-years-old female patient received BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE), dose 2 via an unspecified route of administration, administered in arm left on 22Mar2021 09:00 at the age of 43-years-old (Lot Number: EN6204) as single dose for COVID-19 immunization. Historical vaccine included BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE) as first dose on 01Mar2021 at the age of 43-years-old for COVID-19 immunization (Lot Number: EN6198, Anatomical Location: left arm); started period couple days early after first vaccine from Mar2021, caller reported she got the first Pfizer BioNTech vaccine and shortly afterwards she started her period, which was a couple days early, but it didn't stop for 10 days. It was really, really heavy bleeding along with clots and things. Medical history was none. The patient's concomitant medications were not reported. The caller asked if prolonged bleeding with periods was a side effect of the vaccine. She stated she had both doses of the vaccine and had this issue with both. She stated she knows there has been other woman who have come forward saying they have these things. At the time, her doctor had not heard anything about any reactions to it. Her iron has been low and she got tested for anemia and was anemic now. She has had her second period since the vaccine and was on day 16 of period. It was still going on strong and she was wondering if this was something that Pfizer has heard of happening after the vaccine. She had first BionTech vaccine on 01Mar2021 and her period started a day or two after that. It had gotten worse, but did subside. She was normally super regular and super normal with her periods. Stated she did have another small period in between the first and second vaccine, but that only lasted for a day, which was really weird for her and did not usually happen. Had the second dose 3 weeks after the first dose on 22Mar2021 and a couple days after that her period started and she was now on her period and on Day 16 and it's gotten worse. This one stared early May, 03May2021 and was also still going strong and really wants this to be resolved since going on her honeymoon soon. Caller clarified event of periods. She had been checked for anemia in Apr2021 and told she was anemic. Has also gone to specialist to see what's going on. They suggested a biopsy to rule out that there was nothing else going on. If nothing else works they are talking about doing an ablation to stop the bleeding or a partial hysterectomy, where they just take the uterus, since they know that's causing her anemia and since the bleeding won't stop long enough for her to get her blood supply back up where she needs it. Has not had any energy and it's hard to breath with no oxygen in her blood. Physician office was for period still ongoing and strong, really heavy bleeding with clots, iron low, anemic, no energy, hard to breath with low oxygen in blood, saw a specialist. The patient experienced period still ongoing and strong, really heavy bleeding with clots in Mar2021; prolonged bleeding with periods in Mar2021; had been checked for anemia in Apr2021 and told she was anemic/ iron has been low; Has not had any energy; it's hard to breath with no oxygen in her blood. The outcome of events was not recovered.; Sender's Comments: Linked Report(s) : US-PFIZER INC-2021568087 same patient/drug and different dose/event.