Trying to figure out knee issue

So I'm trying to figure out what I did to my knee and how I should proceed from here. A little over a week ago I went for a run on a snowy day. Because of the snow, slush and ice I was running in the road. As a result I found myself turning a lot watching for traffic. About 4 miles in things in my right knee and hamstring seemed off so I cut the run short. The next day I started feeling, what I can best describe as a "catching" or snapping feeling in the back of my knee when I walked. There is no pain, just a little tightness behind my knee. I decided to take a week off to see if things improved. The catching became less frequent but I developed a clicking/ popping sound in my knee cap. Yesterday I swam and things felt fine. Only the occasional popping when my leg was straight. Today I went for an easy run with some walking built in. When I ran there was no catching sensation or popping but there was when I walked. Once again there was no pain just a little tightness. So has anybody had a similar issue? Any thoughts? I dont want to take too much time off because I have Ragnar CapenCod in May but I also don't screw up the season. Thanks for any help.