exact "probabilities" (the actual term is "incidence" here, in fact) are not known precisely, because that's what they are: rare. They depend a lot on the conditions of the people who get them, including any not-known infections going on at the time, allergies and so on. At any rate, if you're where your flag says you are, I would not be too worried, there's barely any record of anything that hasn't been recovered from fully with proper medical care after the vaccine in our regions.
With any new medication, including and especially new vaccines, there's always increased surveillance of any undesirable effects (regardless of whether they are linked to the new medication or not, in fact), so they can be treated accordingly immediately to avoid any grave outcome. It's in particular still unclear that some of the reported effects are really due to the vaccine, as numbers are comparable (sometimes even lower due to statistic fluctuations) to general population, so the only things we can undoubtedly link to those vaccines specifically are the more common ones: muscle aches, mild to medium fevers for the following ~48hrs, etc, as well as allergic reactions in some rare cases (usually immediate or in the ~15mn following the injection, which is why you stay in observation during that time)
Other more rare things may or may not be linked to it, we really don't know at the end of the day since the numbers are so similar to unvaccinated cases of the same effects, and you should be reporting anything unusual to your health authorities so it can be recorded and investigated anyway (and if it forebodes anything potentially harmful, so they can take care of you before it gets to that hopefully)