OPK error or could I be pregnant?

Alacia
So it's been 4 days since my first positive opk and I'm still getting a smiley? Is this normal or could I be pregnant?  It's my first opk so I don't know if this is normal...I've been really tired and gassy lately but this is driving me crazy!! I don't know what to think. My first smiley was on 05/15