Ovulation/Implantation

Sara

I have 3 apps tracking period/ovulation. One says I ovulated yesterday, 1 says today, and 1 said a couple of days ago. We’ve done it everyday throughout the fertile window. This morning, I saw blood. It was only spitting, but bright red and no mucus with it. Could this be ovulation bleeding or implantation taking place? I’m also having back cramps and slight nausea.