funny, I'v also taken my shot on the same day ..
when u take this shot ur body "thinks" ur pregnant but after two days ur probably still ovulating and no pregnancy if occurred can actually show at this time..take it easy and try testing in a week or so to check if the shot has worn out..after that u can test again to c if u get the REAL positive..
Good luck!
Novarel contains HCG and that is what your tests could be picking up since you have tested so close to having this shot.
When I get a shot of Ovidrel as my trigger and then have the IUI 2 days later, I do not test until about 7 to 8 days out to check to make sure the HCG is gone so when I test again closer to the day of my expected period, I know the results are not being influenced by my shot of HCG.
Anyway, this is my guess but a beta blood test would be the more accurate.