Shooting Pain After Treadmill?

I have recently started to train on the treadmill to lose some weight and increase my cardio. I have been doing it for about three weeks and have gradually increased the speed. I started from 4.0 and now I am at 5.4 for 30 minutes. I have recently been experiencing sharp shooting pain and aching pain in my left foot after about 15 minutes into the run. I have proper running shoes with support. Any advice on how I can stop the pain and still continuing to use the treadmill.