Negative to positive

Georgina

So glow says I should of ovulated on the 30th of June, 3 days later I had a slight tinge of blood in my discharge. I thought this may be implantation as we baby danced a lot on my ovulation week. Took a test 2 days before af as I had a feeling. It was negative. Af is now 2 days late and normally starts on the day glow says.. I’ve been having symptoms. Has anyone had a negative test by testing before af due and then had a positive after missing af?