What’s going on

Today makes day seven that I’m made according to flo app, I did a blood test on my third day late and it came out negative, I just took this test a few minutes ago and still -, I’ve been cramping since last Sunday evening I believe it was, and every day this week, it wasn’t bad yesterday, then today that we’re so rough compared to what they have been, I was sure af was coming, I have yet to bleed a speck this whole time, has anyone else experienced anything else like this? What was the cause?