Bfp/Bfn

Had nexplanon for almost 6 years. Had af started on Christmas Got it out Jan 14th started again the 18th of Jan. Hubby and I bd during fertile week and after been cramping and having some symptoms I tested 11,12&13th al negative. Today suppose to start had some cramping last night but no af. I’m going to wait till the 18th since it came 18th last month but took a test and there was a extremely faint blue but it was going sideways and now it just looks like a blue smudge. I’m confused. Could it be starting to detect hcg!? Tried to get pics but was blurry