Stressful meaningless numbers

So, my CEA, a measurement that can be correlated with colon cancer, has slightly been on the rise since the chemo began. I don't have much faith in the number anyway, as it was normal in my case even with a tumor still in my body. And it's still within normal limits now, just trending upward. I have no doubt at all that this trend is completely meaningless, but it still ruined my afternoon to see the latest lab results today and see that relatively big jump. I know that it's crazy to worry about it -- I have real things to worry about, and I'm trying not to worry about even them -- but I wish it hadn't been that way.