I just typed this up on another thread; you use to hear about this but it’s not so common a subject anymore and that could be a from a few different things. It’s called 'test nipple" you usually get it pretty early in the cycle. You didn’t provide much info so I can’t tell you if you are even in the time frame where it could be gyno. Also your body fat can and will cause you to aromatize test at a greater rate than a skinny guy, just a shitty fact.
We could use some stats to help us guide you in determining if this is infact gyno.
As far as your dosage, dude plenty of guys run 250mgs a week for their first cycle and get great results. Roughly that is about 2 and 1/2 time the high end of natural production, depending on age and the such. I think a 250mg first cycle is a smart logical choice as it allows you to see how you react to a lower dosage. If you get great results then why go to 500 the next cycle, you could stay at 250 or just bump it to 300-350. Also it allows you to learn how to handle the estrogen from just 250 vs 500 for your first time. Now a lot of guys don’t have any issue even at 500 but you don’t know until you do it so being cautious and smart is always the way to go. Seriously I actually feel better about the future because someone is being intelligent about their first cycle.
I know people write all sorts of stuff about using too much Aromatase Inhibitors. It is very easy to over use them and tank your estrogen. Remember we need estrogen to build muscle. I don’t think your aversion to Nolvadex is something to stick to if you are experiencing gyno. Really Nolvadex is the idiot proof way to avoid gyno. Both ai and Nolvadex work and if you stay in this cycling world you will need to develope your skill set with both. For now if you still have nipple issues and you notice a lump forming then use Nolvadex. Probably 10mgs EOD would be a good start for gyno protection. Heck even if you can’t for sure determine if it is gyno then using a low dose of Nolvadex to see if there is a change isn’t going to hurt you. So if you are one of those guys, like so many others among us, that is going to worry and worry about this then just try a little Nolvadex to see if it goes away. Again I bet you are just having the old 'test nipple" but there is nothing wrong with trying something just for peace of mind. (If you were going to use an AI I would have a different stance.)