I've used progesterone cream regularly for many years, and still haven't noticed any weird effects at all. Though, I don't use all that much at a time either. Using it may have contributed to my losing every last inch of belly fat. I haven't tried growing breasts, and don't take any estrogenic herbs or bio-dedentical pharmaceuticals except an occasional 1/8th pump of estriol cream on my nipples.
I only notice that these creams seem to make me feel more physically replete, rather than drawn and burnt-out from stress. Can't comment on what they might do for breast growth, since none has occurred. In fact, my life-long slightly noticeable moobs have shrunk to almost zero. Though, this is probably largely due to migrating to mostly ketogenic diet. Still, progesterone may be helping mitigate estrogen receptor activity in the belly fat region.
I don't notice any overt sensitivity in my nipples. That being said, I'm not sure what effect progeserone may have had on my T levels. I hope it is still high, but it's difficult to subjectively say without testing. Since I'm actively suppressing T conversion to DHT, many of the subjective "markers" are absent.
It appears obvious that P in the presence of high levels of E is quite a different experience from P in the presence of low E, and normal levels of T.