I have been getting headaches too and a couple turned into migraines.My Dr told me to take panadol as soon as i start to have a headache and nip it in the bud! He also said its due to oestrogen levels from pregnancy.
Also,i wear glasses and pregnancy can also interfere with eyesite so if you have a problem to see your optomotrist.I needed a new pair of lenses and was only tested the yr before.
Drinking a glass of water before bed and first thing in the morning can alleviate dehydration symptoms too.