I did the prediction thing, and it was right about boy, but it says I'll have him March 4 th and he…

I did the prediction thing, and it was right about boy, but it says I'll have him March 4 th and he will be 7 lbs. not possible. He was 2 lbs nov 24, and I'm 30 wks measuring 30-32 cm march 4 puts me a week late, I believe if he stayed in that long he will be 10 lbs lol