Lh surge question


So yesterday my lh line looked pretty dark and the app listed it as one level below the surge. That was at 6pm yesterday. Overnight my boobs were sore but nothing else. Today the line is almost nonexistent, which usually happens to me after my surge. Is it possible in that 15 hours I had my surge or why else would my line go from so dark to gone? It’s cycle day 8 but I have cycles from 24 to 40 days so it wouldn’t be crazy for me to ovulate that early. I just don’t typically have levels drop unless I already ovulated so curious about others experience! Thanks!