Okay, let see if I can explain this further.

So I have started (for ~3months) doing strength training at the gym (shoulder press, bench press, etc..) and noticed that my chest has sort of gotten.... bigger? The ones like when girls just hitting puberty. Which is a bummer, as I wasn't planning to getting boobs. Was aiming for a more buff chest, not like growing a pair! And the nipples are getting so prominent, that it shows over the shirt I am wearing.

What have I done wrong? For more info, my diets remain the same, so I am incline to say that this is caused by my training regime. Thoughts?

I don't have both the before/after pics, and I did not measure my body fat percentage. I have my weight figure, and it does not change much since I started strength training. I am not sure, could it have possibly be an issue of poor form? or maybe I am going at it too hard, or with not enough reps?