Julie, sorry you didn't get answer.
The site refreshes/updates everyday around the time you posted. So for 15-20 minutes it's down. At least that is what happens with me. You must have got caught in the downtime.
Grab some mid cycle tests when you can to see if the dose is good or not.
Anytime you get an unusual reading its best to test again immediately just in case stripes bad. If it wasn't a bad strip and test was correct, it might become an issue.