Well I am now late

I've taken a test just to be sure. And it was negative. I am thinking maybe it's the change from cows milk to soy milk or it being just 2 months after I took out mirena and my body is trying to figure things out. I only had mirena in for 2 months though so idk lol idk if maybe it's just still to early to detect anything on a pregnancy test depending when I ovulated. Who knows. Anybody else have things like this happened when switching to soy or after mirena?