Well every person is going to be different. with the last 3 m/c I had, I had a really bad heache with all 3 of them. It doesn't always mean your going m/c but with me that was the case. I hope this helps you out. Good luck with everything and I hope you have a healthy 9 months.
A change in homone levels can cause migraines, I had them at the begining of my pregnancy and Im still pregnant, I dont think thats a sign of miscarriage, maybe a surge in hormones if anything...good luck
im sorry im really not educated with all the progesterone/hormone levels and all that, but i know that headaches, even severe ones, are totally normal in pregnancy. i know its still really early but i had ones like that too where i felt nauseous. so did my friend, she had to stay home in bed all day when she had those headaches. hope you start feeling better, and good luck!