So I am 3 days away from my period. I took a test a first response yesterday and got a faint positive. I had taken a dollar store one in Sunday and had a faint faint line. So I bought a clear blue digital with weeks estimater and it came back negative. This morning I took a ovulation test because I had no more pregnancy and instant positive. Went out bought another first response and a dollar test and both positive. The lines are getting a bit darker than yesterday. Why am I not getting a positive test for the digital?