Help.

How did everyone else react to something like the following? Because frankly, I have NO clue what to do.

Today (Wednesday November 9th 2016) my little sister (14) came to me (by force of her boyfriend) to tell me that over the weekend, she had lost her virginity. She had asked me not to say anything to anybody, and if I could possibly take her debt card and buy her some condoms.

I'm happy that she's trying to take action so she doesn't do what I did and get pregnant at 16, but I'm just worried. Should I tell my parents or should I let her do it when she's ready? I'm terrified at this point.