Hcg neg but pregnancy test progressing

Nik

I’m still so confused I gave blood two times and yesterday when I noticed a darker faint positive (pink color to line) she said it was negative . Today my test is getting darker . they have been progressively getting darker yet no hcg how could that be ?? Dr said possible chemical pregnancy but if that’s the fact I didn’t have hcg regardless so why are my tests getting darker ? I have very extreme positives with lh and temp rise also pregnancy symptoms. Anyone have a similar experience