Could I still possibly be pregnant?

Titiania
Today makes my period 17 days late, I've had every single symptom you can imagine. Nausea, heartburn, cramping, sore beasts you name it. Some tests gave me a BFN, while others gave me a faint positive. I've gone to the doctor twice, once on 2/20 and today on 3/2, still their test shows a negative. My last period was on 1/16/17. Has anyone else been through this and ended up pregnant?