I'd say you look fine and have a good foundation and thickness.
Maybe this will help some. For me, I have genetics that leaves some fat on my pec areas which are the last to be shed when dieting. Not a lump, but general fatty tissues around the pecs. So, I try to stay lean all the time (plus using Yohimburn to get rid of it >> and it's working!).
I'd say lean down some and see how it looks. If you had a lump once and now it's gone, you're one of many. Teenage gyno is not too rare. I wouldn't sweat it.