Only 1 day of positive OPK normal?

Stacia

I have the digital ClearBlue OPK, and I only got one smiley face out of the 3 days I tested. First day, negative. Second day, positive. Third day, negative again. Is this normal to not have more than 1 day of a positive OPK?

It looks like it was ALMOST positive on the first day I texted. But was still a little lighter than the control line. We didn’t BD until the end of the day I got a positive result in the morning. Was I too late?