That's so great you're doing the Hope 5K, we'll be thinking of you too!
I'll be hoping for good news for you on the MRI; I have periodic headaches like that, last about 3 days and nothing really works against them. I've had MRI's and nothing shows up, so have decided they're allergies, but I'll keep having MRI's anyway, just for the peace of mind;
no pun intended
Love, Lolly