With the rules only Fighters can swap bonous feats every four levels, but other than that no. I think it's a common for DMs to allow some retraining but it would be a houserule.
Exactly. By the book, you're just out of luck. There are very few GMs that would deny you a new feat, though, and most bonus feats actually tell you what happens if you take it early
I think I am out of luck. I am looking at the Lore Warden fighter Archthype for my PFS character. I needed combat expertize at first lvl. But you get it free at second.