I got the j&j vaccine and since last night got a few sharp headache that last a second and it happened this morning as well. should i be worried about blood clot. thanks?

Very unlikely (so far 1/1,000,000,000. Almost all woman). But can’t be absolutely sure. If symptoms last all day and are unusual (FOR YOU) would present to ER at big hospital (for you -> Johns Hopkins or University of Pennsylvania)

The risk of a serious blood clot is very very remote and not worth worrying about. The risk for woman is less than one in a million and for a man it is infinitesimally small. Wish you good health!

NO only females between between 25-48 have come down with blood clots. I had COVID last year and received the J&J vaccine in MARCH and only side effects have been fatigue .Mild symptoms are expected so don't worry.

Not to worry about something that occurred less than usual ( not more ) The incidence of blood clots in the general population is much higher than the 1 in a million seen in the 6 cases . Anyone anytime who has swollen legs , suddenly , needs to be evaluated for ,DVT’s in the legs. Part of the work to do with your primary Doc is to pre identify , things you are at risk for.