This is my biggest concern. I'm waiting for my order from Bellas to come in.
I plan to go on birth control after maybe 6 months on PM. If I stop taking PM, will all (if any) boobage gained just gradually shrink? Because that would just be a pure waste of 6 months.
THAT WOULD SUCK.

That may be highly individual. Some girls gain over a short span and keep it, while many others quickly shrink after stopping. You may have to look at this as being in it for the long haul. If it were me, if I reached the size I wanted, I'd keep taking maintenance doses for a long period(like a year) just to be sure. You have less of a chance of losing your size then. But that's just me. ;)

Hi, I know that some people have slowly come off PM so lowering the dosage once you've obtained what you want and coming off them slowly. Same way as I came on them that way I plan to come off them that way too.