12 DPO got a faint positive, tested ever since and bfn?!?

Madison
What in the world is going on?!? If it a faint pos on my 12th DPO and was so excited. I've tested everyday since and have gotten all negative since? Has anybody ever had this happen and end up pregnant?!? Kinda wondering if I am having a chemical pregnancy! I am so confused, the only thing that gives me hope is I have all kinds of symptoms. Anyone had anything like this and it come out good?!