I am a 28 year old female with no known health problems. I have had a sudden onset of "pins and needles" sensations in my left arm along with a little numbness. It starts in my tricep area and moves along to the top of my hand. It comes and goes and has been this way for about 24 hours. The only change I have made is that I started a birth control pill about 3 weeks ago. What could be the cause of this?