Severe headache

Ca
I'm 35 weeks and 3 days. I've had a constant horrible headache since 8pm and it is now 6am. I've taken 3 tylenol in those hours and it's never gone away. I know I'm not dehydrated. Should I call my Dr or just wait and see if it goes away? I'm not having any other symptoms. My blood pressure has always been normal also.