What Causes Constant Dizziness,light Headedness And Headache?

for 4 days I have felt light headed and dizzy. This has been a constant feeling, which is worsened by standing or walking. I also have a headache which is right at the front, on my forehead. I saw my doctor who took my blood pressure and send me away for a blood test. Blood pressure was fine but I'm still awaiting blood test results. I'm a 17 year old female. DO you have any idea what this could be and how I could get some relief from the constant dizziness?