It is definitely NOT 2.5 inches at 6 weeks pregnant.
AT 6 weeks is the size of a raspberry. Yours sounds more like 12 weeks, to be honest.
I work in an abortion clinic, AND I personally assist with abortions, so I know what each gestation looks like.
I have also had 3 abortions.
AT 6 weeks the fetus would not be 2.5 inches long.