In my sons case, his bone age was checked annually (approximately), not every 6 mos..  His bone age was 8 yrs. at 7 yr. 5 mos., remained 8 yrs. at 8 yr. 5 mos. (Feb. 2003) then advanced to 12 yr. 6 mos. at 9 yr. 7 mos.(May 2004).

In June 2003 we noticed pubic hair was starting.  We were unable to get an appt. with the endocrinologist until August.  At that time, they looked for other physical signs of puberty (eg measuring testicles).  Based on the exam, they said it was not early puberty.  Based on labs, though, they upped his Cortef.  Labs were repeated in October and Cortef was increased again, but we were told other results indicated early puberty was not occurring (did not do Lupron stim at this time, just LH, FSH & testosterone).  Pubic hair also disappeared with increase in Cortef.

Endocr saw him again in November.  Cortef was increased again when those labs came back, but Bone Age was not done at that visit.  Labs repeated in Feb. with no change in dose.  Bone Age was done at May 2004 and so in a little under 15 mos., his bone age advanced by 4 yrs. 6 mos.  Cortef was increased and they decided to do the Lupron stim test.  That was done in early June, and as I said in my other post, the results were "not clearly diagnostic either way".  They decided to start the injections anyway, based on the bone age.  By the time all the arrangements were made, it was the end of July before he got the first injection.

That pretty much is a detailed history of our experience.