so 13 Germans had a blood clot after taking the AstraZeneca vaccine. they have vaccinated 1.6 million people. that's 1 in 120k people. Norway has vaccinated 120.000 and 3 people got blood clots. that's 1 in 40k people. this isn't much to go by in terms of determining the frequency of side effects, but it does give a ballpark figure.

the figures i can find suggest that birth control pills carry a similar risk of blood clots. so there's that.