I think most guys experience that. It sounds like paranoia or phantom gyno. I always thought I was getting gyno on my early cycles, but I never did. My nips are a little bit puffy, & it seems a little worse when "on". It sounds like you are the same. If you dont feel anything, I wouldnt fear gyno unless you do.
You can try Prevent by Xtreme formulations, its designed to treat "pseudo-gyno". There are a few threads on BB.com about vitex reducing puffy nips.