Help!!!

Ambir
Okay all im scared and not sure what to do......at 9dpo i got a pretty good positive pregnancy test and that was on the 15th and today the 19th ive been getting negative test not sure whats going on scared of a miscarriage or idk whats going on also is there a certain point where pregnancy test cannot record the hcg any more bc its to high? Any input would be great thank you! !!!