I hear you on the part about wishing I had kept a journal with my daugther (now 3 yrs). It would have been so helpful.
This happened to me last week. The headache lasted for 48 hours, this dull ache in the back of my head. I also kept feeling like I was sunburned, sort of warm and uncomfortable. I took 2 tylenol, because after over 24 hours of the headache still being there, I had had enough. The tylenol didn't help much, and I drastically increased my water intake. I also spent the entire evening with ice packs on my head. That helped a lot! (I don't know if I was running a low grade fever, I never took my temp...)
It seems like so many strange symptoms are "normal" symptoms during pregnancy. I dont know what was causing mine, and I am glad they are now gone. I suggest calling your OB or midwife if you feel like you are getting worried about it. I wasn't worried about mine, I often get lots of headaches, but you know your body...if it seems odd, I wouldn't hesitate to call and talk to someone.
Head to bed early tonight if you can! I hope your symtoms go away soon.
mama to and, due in November