My nipples were very unnoticeable before I started. Actually, I couldn't even describe them or compare, because male nipples aren't really my thing, mine or otherwise. But yeah, since I've started, they've exploded in size and they're like spears. Hard to conceal from pointing under a shirt, which is sometimes a bit annoying, even though I couldn't be happier that they've taken up to growing this fast. Besides being really large, they seem to be in a hurry to get somewhere, because they protrude out from the rest of the boob materials quite significantly.
As for pain, I'm pretty much the same as some have said. If they're not hurting, I'm worried that they've stopped growing or something. Then get relieved when I push on the nipples and the familiar pang of pain shoots through. It's like an assurance, saying "hold your horses, we're getting there as fast as we can". Sometimes I've done this check and have found out the pain to be quite significant indeed, which makes me feel like I had skipped on the whole thing. But yeah, I'm not into pain as such, but it means I'm going the right way.
