Have the headaches just started since you became pregnant? I suffered with headaches really badly around 17 weeks and my midwife didnt seem worried at that time either. She just told me to take paracetamol when needed. They too stopped not long after they started for me tho!
I hope you start feeling better soon. Ask your doctor about your bp next time your there but at the moment I dont think you have much to worry about providing it doesnt rise!
Hmmm I hope this made sense!