Faint positive on clear blue?

[Indiana12]

I’m 1 day late for period. Cycles normally around 35 days long. Took clear blue this morning and could see faint line. Read within 10 minutes. Not had this before on a clear blue. Is it just an evap line?

Not sure how to upload the image here - can someone help?

@Indiana12 if your new to Mumsnet it doesn't allow you to post pictures for a while I don't think x