Anecdotal reports. Look 20-25% of ALL pregnancies end in miscarriage. It is one the least spoken of heart breaks around. Just because you take a flu shot if you are pregnant and then you miscarry does not mean that the cause was the shot.
Sorry post hoc ergo propter hoc is not convincing.
And I say that even though I am not an advocated of flu shots in the first place
read the time frames involved in the stories and there is enough reason to suspect the vaccine.