Lmp July 20. TTC. I took several hpt Sept 6 - 14. Faint lines, hcg blood on oct 3 was negative. My doctor is really concerned I'm pregnant without hcg. I have a scheduled ultrasound for a week from now. I have researched a lot and read stories about women who only found out they were pregnant by ultrasound and usually in their second trimester. Has anyone else experienced this???