I got mine yesterday, too!
When I read your log this morning, I felt pretty decent. Just a sore arm and I woke up a few times overnight with shivers.
And now in the afternoon.... there's the headache you mentioned!
I too had a headache, and some minor upper body aches. But I get headaches so often I couldn't be certain it was from the shot.
Still, the feeling of freedom and safety is worth it!
Woo! (For the getting it part, not the feeling crap part!)
And yes, feel relieved, although won't feel fully so until kiddos are able to get it too!