Thanks for the query to H.C.M. Forum. Paragard
I U D is copper fitted I U D and most potent , so there is no chances of any pregnancy
As you mentioned that home pregnancy test is negative twice , so why worry.
However it may happen that , if I U D not inserted at proper site or persons are not trained than there are chances of pregnancy.
Consult a gynaecologist and get his opinion as physical examination is very important .