half marathon training advice

Hi

Last week I started off feeling really low with a bit of a virus. I didn't get as much mileage in as I would have liked. I tried to make up for it later in the week when I felt better and failed to think how this might effect my long run of today. I had planned to do 12 miles (HM is in two weeks) but having done 7miles at 7pm yesterday, I only managed another 7 today. Technically this is quite good as I've done 14 miles in the last 14 hours. On the other hand, I'm not really getting the benefit of going for longer am I? I probably could have gone longer today if it weren't for a sore foot. I get a pinching, cramping sensation under the arch. I've tried exercises, taping and stability shoes but sometimes theres no getting rid of it. Other times its fine. My question is, if I want to get a run of 12 miles in soon, would it be a good idea to do it in the week? Or should I let it go and maybe do one at the weekend? Its my first HM, I've gone up to 11 miles two weeks ago, 10 miles last week.