New to running - Pain in outter Calf?

I have recently started the jogging app C25K. It does walking and jogging in intervals. So far I have not moved past the first level (after 2 weeks) because I still get this pain on the right side of my calf (outside) about 15 mins into the workout. I suppose it could be shin splints? But it hurts more when I stop to walk, as opposed to running and sometimes to where i limp the rest fo the way home. It feels better after a few minutes at home and then nothing the rest of the day. I thought the pain could be my legs using muscles it is not use to, but when does the pain start to go away? and wouldn't my legs hurt all day? I know I could also not be using the right shoes and I plan to buy some if this is something I plan to stick with. Anyone know what this is? Any tips? Oh and also I do light stretching before work out and then a little through out the day as well. Any help would be appreciated!