You can just say " блин ". It goes well in all cases)))

Ё-моё! Ёпрст! Мать моя женщина! (surprise) Да чтоп-тебя! Ёлки-палки! Бляха-муха! Б-лл! Оппаньки! Приплыли! Пардон! Здра-а-асте! Уй-ё! (if you've hit your finger hammering) .....

Usually we say "Ой!" (Oj!) in the similar situations when English-speaking people would say "Oops!". For example, if we drop something which is not too expensive on the floor.

You could say also "Упс" - lot's of Russians say so. But in general people usually say "ой!" )) "Ох" has mostly negative connotation, like if you're complaining (ох и тяжелая у меня работа!). "Ах!", "Ух!" or "Ух ты!" people usually use when they're excited about smith. Or surprised) (Ух ты, как красиво!", "Ах, как здорово!"). Actually there are loooots of such interjections in russian (эх, уф, ай, оп, опа and hundreds others) so I'd really recommend you don't pay much attention because it's very easy to confused! Just know these general ones :)

https://www.youtube.com/watch?v=PgoZd3i3CUE https://www.youtube.com/watch?v=90o6Jk-dHvw These two animated cartoons could shed light on some of Russian interjections. :)