When I ran my half marathon, I was almost two weeks late for my period. I assumed it was from all the running and training I had been doing. I've known that to alter cycles before.
By the Thursday after the race, November 10, I was tired of waiting and on my way to class that night, picked up a pregnancy test.
I know that you are sometimes advised to take them first thing in the morning, and we always have before, but I wasn't willing to wait this time around. When I got home from class that night, it was the first thing I did. And sure enough, it was the clearest positive result we've ever received. (Just a reminder, our previous experiences are here and here.)
I'm feeling much better now about my less than satisfying half marathon. Not only was I feeling sick, I was pregnant too!