Hello Imweird.
I'm also a 28 year old non-transsexual.
I don't have a significant other, but I think I can offer some helpful advice based on my own experiences. I don't try to flaunt or conceal my breast development. Nobody other than 1 doctor has inquired about it (and that was only because she was listening to my heart and lungs for a completely unrelated issue.) I suspect people either don't care, don't notice or are just too polite to say anything to my face. My advice is try not to draw attention to yourself regarding your budding breasts. If you're comfortable with your new breasts, I suspect this can go a long way with how others perceive you. If you act all embarrassed or blustered about your breast development, I tend to think people's attention will naturally be drawn to them.
As Elain has mentioned, taking the herbs to grow breasts does entail chemical changes elsewhere in your body. Your libidio for instance could very well decline as you go further and further on the NBE journey. Your fertility could also suffer as well. If you're not okay with these changes, I strongly suggest not taking NBE herbs.
On a final note, are you okay with giving up swimming and otherwise going topless in public? I can only imagine the kind of stares I would get if I tried to go topless in public now.
Feel free to send me a pm if you have questions for me or whatever.