Is this my period?

Hi my name is Emily and I am almost 14 it all started in the car I had a sudden headache and my back was aching then my lower stomach felt like it was crushing together and a thousand needles jabbing me in the side I was in Intense pain I was crying so hard I thought I was dying I couldn't even move a muscle. I thought I was Constipated so when we got home I went to Toilet and that's when I noticed a drop size of dark brown discharge so I put on a panty liner and only a few min. Later I felt wet and sticky I  went to change my liner  it was covered in a dark brown discharge with a tent of a deep red then when I would wipe it was the color of dry blood. Then the next day it got lighter and lighter and then went a way around 6:30 am is this my period???