kyasseen you don't know if your count went down for that short period time unless you got a platelet count when you noticed the blood blister. (just my opinion)
I've had ITP since 1989 and have received a flu shot (inactive) every year starting in 1992 (28 years) and have never had a problem! In fact I just got my flu shot this morning, and due to my age I'm given a high-dose shot and that has never bothered my count either.
Like mrsb, I would much rather deal with a drop in count than catch the flu, especially now!
"Instead of wasting your time worrying about symptoms, just get it checked out" -Nieca Goldberg, MD