Ugh help

so I'm 37+ 3 and I'm not one to get headaches. so this is weird for me my entire pregnancy I never got any headaches and today alllll day I have had this really bad headache that won't go away.... I napped thinking it would help but nope nothing. current 11 at night and it's going on ...what should I do? also I've had normal BP throughout my pregnancy and part of me wants to check if my BP is high but it's 11 at night.... helpp