I worked up the nerve.

[Katharine]

용기를 내다.

 work up one's (the) nerve, get up one's[the] nerve (to do),

ex.)The first time I had my period, it took me five hours before I worked up the nerve to tell her.

       (period; menstration)

 pluck[summon; screw; muster] up one's courage / take[collect] courage[heart] 

[Jeff .C]

"The first time I had my period"

in this sentence, what can I translate "period"??! just terms of time?!
Could anybody let me know?!

[Katharine]

Period in this sentence refers to the menstruation period in women.So, the period is translated to 생리or 월경, and the first period is to 초경 in Korean.