HELP PLEASE

Tiff • TTC #1 ❤️
Been trying for 9months now since miscarriage.
I came on my period 5 days early.. I logged it into glow and now glow is telling me to take a pregnancy test... IM STILL ON MY PERIOD.. Light but it's still there?? 
Do I actually take a rest or what? I've never ever heard of testing whilst on...