Could you post a link to information on such clots? It would definitely help to put these into context and relegate these into a concern around frequency, rather than how long they are.
Do COVID-19 vaccines cause blood clots?
The Moderna or Pfizer-BioNTech mRNA vaccines have not been shown to increase the risk of blood clots in multiple studies. However, two COVID-19 vaccines are associated with an extremely rare syndrome known as vaccine-induced thrombotic thrombocytopenia (VITT). It was discovered in March 2021 in connection to the AstraZeneca COVID-19 vaccine and then later with the Johnson & Johnson COVID-19 vaccine. In rare cases—2 to 20 per million—antibodies that the body produces as a side effect of the vaccine lead to uncontrolled activation of platelets. This causes both low platelet counts and blood clots to form.
The occurrence of this rare antibody is a random event without a known association with a person’s medical history or any particular conditions. “There’s no way to predict who’s likely to develop the rare antibody that triggers VITT,” Abou-Ismail says. “While it is a little more common in younger women compared to other populations, it remains exceedingly rare even in that group.”
If deciding whether a COVID-19 vaccine is worth the risk, Abou-Ismail tells his patients that ”mRNA COVID-19 vaccines are safe in patients with a history of blood clots or increased risk factors. The risk of developing a blood clot from COVID-19 infection is far higher than getting a blood clot from a COVID-19 vaccine.”
Article is dated but may have some useful info
https://healthcare.utah.edu/healthfeed/postings/2021/07/blood-clotting-covid19.php