How many swimming pools full of vaccine do we need?

If we brought together all the Covid 19 vaccine needed for the whole world, how much space would it fill up? An Olympic size swimming pool? We do some back of the envelope sums. Plus - we look at the increased risk of clots from pregnancy. Last week we looked at the increased risk of getting a clot from taking the combined contraceptive pill and compared it to risk of possible rare clots identified following the Astra Zeneca jab. How does pregnancy compare?