What Can Cause Elevated Headache With Nausea?

Hello,Throughout the day I have had a moderate headache and around 11:00PM I took some excedrin. Then around midnight I starting have chest pain right behind my chest bone which quickly worsened. I didn't know if it would be ok to mix pepto-bismol and excedrin so I waited to see if the pain would get better. Around 2:00AM I took pepto because the pain wasn't any better but then my pain was much better after taking it. An hour later the sharp pains came back. I started experiencing nausea as well. When I stand up I feel slightly light headed but it goes away qucikly. Should I be concerned?