confused much

So my period went from 8-10feb 
I took opk after that and got my peak at 19-20 feb 
On the 27th a got sick i the morning (as in throwing up I know tmi )
On the 28th took a first response test it was negative 
On the 1st march I took another first reposes with a vvfl 
So I took a clear blue digital with weeks indicator on it and it came back pregnant 1-2 weeks 
I am so confused coz glow nuture says I'm 3 wkk + how can that be it hasn't even been two weeks  post ovulation ?