Confused- please help!

I had a very faint line on February 5th. That same day I took another rest and it was negative. I did blood work on the 11th and my doc says no hcg. I highly doubt it was a faulty test bc I was have super faint lines prior the “visible to the eye faint line”. My tests have been negative since. I’m thinking chemical or missed miscarriage. Shouldn’t I have a “period” by now? I’m so confused.