Fsh level while stimming, where should they be at?

Emiley's post below got me thinking. Co.oper checks your fsh while stimming. Does anyone know where they want your fsh to be while doing a low stim cycle? I would imagine it's different for everyone since we all start on cd 3 with different levels. Just curious if there is a happy number. the point where they know that the meds are working and that it's not just your own fsh in play.

My first ivf (non-Co.ooper) my cd 3 fsh was right around 6, A couple days into taking stims my fsh raised to 25. My RE at the time was pleased with this number and I continued to take around 350iu of fsh a day. My first IVF at CC my day 3 fsh was 8 but it only rose to 11. I know that the goal is to only get a couple eggs with low-stim but it just seems like there was still room to push a little further. Thoughts?