Possible to have a positive ovulation test multiple days?

So I had a positive ovulation test on Friday, checked again on Saturday and still positive so figured that was my 24 hr window. Just took one again today (Monday) and it’s still looks fully positive. Is that possible or are these tests inaccurate?! I’m bummed because we didn’t try to conceive after Saturday. So hoping it worked doing it on Fri/Sat!