With my DD I didn't get a BFP until 12 weeks when they did a CT Scan to check for ulcers that prompted them to do b/w. While all of their urine tests came back negative a quantitive HCG showed an obvious positive, as did the CT Scan and an ultrasound. With my DS I didn't get a faint BFP until 18 weeks. They wouldn't do b/w so I had to wait until a test came back positive. His gender was confirmed at my first u/s.

This time I got it at 15 DPO. I have no idea what caused the delays with my first two.