Ever happen to you?

Meghan
I had some minimal dark brown spotting the week before Christmas for a few days. The Sunday before Christmas I got curious and took a test. It was a faint positive. Another one Monday morning, little darker but looked positive. Took a First Response Wednesday evening and had a positive even though the urine test at the doctor that day was negative. Took another test Christmas Day morning and it was a Clear Blue that said Not Pregnant. AF was due 12/27 and still as of today 1/10 I'm late. No signs, not even any faint positives? I had a D&C at 12 weeks in August and had been regular, 9/27, 10/27, 11/27 until December.