7 hour head ache. Headaches are very unusual for me.?

Headaches can be a warning sign of something serious...but first look at routine causes. First, if you are pregnant have you been staying hydrated and taking your prenatal vitamins? Low iron can cause headaches. Also, your neck could be mis-aligned( easy fix at chiropractor ) OR it could be allergies, sometimes your body changes more than one way when you're pregnant. No matter what, it is foolish not to take a couple of Tylenol. Why suffer? That WILL stress your baby... I would suggest that if over the counter pain relievers don't resolve it, you need to get to your OBGYN to discuss diagnostic options.