Pregnany design flaw

Well I'm not nauseous like I was with Annie, but this pregnancy is starting to have it's own little quirks.   Everyday around 2-2:30 I get a headache that lasts until I go to bed.   Weird huh?   The fun part is the doctor can't seem to figure out whats causing them.  I will have to say I prefer the headaches over the nauseousness, but would love it if anyone has a solution to get rid of them.   Tylenol and Advil are out, I'm allergic to both (yes this sucks beyond belief).