Ah, your first kiss from sweet lady chemistry. She sure plays rough, doesn't she? You did the right thing, you called the burn center, and gave them good info. If the burn center didn't tell you to go to the emergency room, then don't, they don't really have the specific ability to help you, at least, not better than the burn center or the poison control center. And I know from personal experience. Just keep monitoring the area, the NaOH will have stopped damaging tissue long ago. Keep it clean, let hit heal, wear your battle scars proudly. And try to cover up better, next time.