If, and it is a huge if, the vaccine has any link to blood clotting, and there is absolutely no scientific evidence to suggest this is the case, then it is an almost negligible risk. A tiny fraction of a percentage.
Depending on what study you read, and the parameters applied, you have between 2% and 10% chance of developing a thrombosis / pulmonary embolism every time you get on a plane (or otherwise sit still long enough - there are cases linked to overland travel as well). Around the same percentage risk for spending time in hospital.
The risk of developing an embolism if you get a severe case of Covid has been placed at between 2.6% and 8.9%. In Covid cases who were treated in ICU's, that percentage rises to around 33%.
The annual incidence of venous thromboembolism is approximately 2 in 1000 of the general population and the annual incidence of diagnosed pulmonary embolism in the UK has been reported as 7–8 per 10,000 people. That means that before there was ever a vaccine, the UK saw around 52,000+ cases a year.
If we ban the vaccine, suspend all air travel for ever, ban any longer journeys, and close all the hospitals, that 52,000 cases a year might reduce a bit. But probably not by much, and it'd be a miserable existence.
Put things in perspective. Even if there is this miniscule risk, and it is very doubtful - given how prevalent thromboembolism is, there's a high chance of coincidence rather than causality - people take these risks all the time and don't even give it a second thought.