Hi Yvonne,
I'm guessing you are starting to have shin splint. Do you feel like a electrifying kind of a pain hitting on your shin when you started running about 10 - 15mins ? also after you finish your run if you massage u'r shin bone using u'r thumb do you feel any pain?
If it's possible try to get a quick MRI check with fisio to find out if it's really shin splint or alternatively most cases you are developing shin splint due to no proper stretches or u'r calf muscles are too tight...
Try to stretch u'r calf muscle before and after your run.. if your are not sure try going to youtube and search for "strecthes for shin splint" and you may find a few good one...continue doing it...applying ICE is a good thing, since you have a race coming soon... you may consider getting this gel called "Fastum" from the drug store and you can apply it.. it's anti-inflam (do check the guide before applying around your shin area before your run) other than that if u are u using old pair of running shoes.. you may wanna check some good one's from asics gel (which i use)..
Hope this helps
-VJ-