Help with OPK'S please?

Yesterday I took my 9th opt and it was the 9th positive one I had. I started testing on the 18th. The line started out faint and became darker. I was just wondering why I am still getting a positive result this many days into it. Hubby & I BD'd every day except Tuesday. Has anyone had this and ended up with a BFP or am I just wanting it so bad that I am making myself believe something that is not true?