11 DPO and BFN

Decided to go ahead and test today since I've been having crazy unusual things happen since Friday, including a low grade fever and major aversion to coffee at home and a rotisserie chicken I picked up yesterday from the store. Either it's my allergies messing with me or just not late enough to detect yet but got a BFN. I'm not out until AF shows her nasty face and if she knows what's good for her, she'll stay away! Anyone else get a BFN at 11 DPO and get a BFP later?