Positive hpt but negative blood work?

Ze

4 days before my period I got positive on clearblue digital with weeks indicator and it was showing 1-2 weeks. Next day I went to dr’s office and she did blood work. It came back negative. Now I’m 2 days late. It’s my first so I don’t know what to think or do. Anyone experienced same thing and result in pregnant? Or does anyone know what this is?