Ankle Pain

Yesterday, I took my run outside since it was warm enough. Wasn't my first run outside, but it did involve a bigger hill than normal. I went through the loop once with no problem, but noticed halfway through the second time around that I had pain in the inner portion by my ankle. It wasn't my Achilles because it isn't in the back. It would go away when I started walking. I iced and rested the rest of the day. Today, it now hurts to walk on it and sometimes when sitting. I'm planning to rest it for a couple days at least and keep icing. BUT, I have my first 5K in 3 weeks, so I don't want to just not do anything! Also, I don't want to back out of the 5K. Thoughts?