I Cam Down With A Cold O 10/23/14, Experienced Chills,

I cam down with a cold o 10/23/14, experienced chills, rested for about 3 days but since I've had a mild headache in the back of my head which has caused for me to feel a little nauseous (no vomit). Today 11/4/2014 12:10 pm, when reaching up to a kitchen cover, looking up and raising my right hand to reach for something, I felt a strong dizzy feeling and started to black out, I brought my hands down, held on to counter and looked down then I tried it again within a few seconds and felt the same way. Should I be concerned?