Confused.. Positive then negative hpt

Ash
So I am 11dpo today.. Last night I got a blaringly faint positive line on an answer brand test- line came up as test was processing and then got darker.. I thought for sure this morning fmu I would have a darker test and positive digital.. Same brand test now seems very faint or negative and digital was negative. Thoughts? 
And now last night on top and this morning on bottom..