Bfp 2 nights ago, BFN this morning?

M.

Wtf?? Saturday night I tested around 5pm on a 3 hour old and got a bfp. Faint, but there. I knew I was still pretty early so wanted to test again to make sure the line was getting darker. Tested again this morning and it was practically negative. Has this happened to anyone before? Most likely a chemical maybe?