How do I say "right at that time"? I'm trying to explain a situation I was in recently in written Chinese. How would I say "Luckily, right at that time Mark heard my voice" 
Would it simply be 
幸亏， 她正好那时候听到我的声音，马上叫了起来“

Thanks for helping out! I'm most interested in how to say "Right at that time" in different contexts
"right at that time" == "剛好", "當時"

"Luckily, right at that time Mark heard my voice" => "幸好當時 Mark 聽見我的聲音(呼叫)"