What punctuation should I have after apartment? period comma? other? please help

Question

This is what happened as she found the apartment.

Finding the correct number at last, I slowly climbed the stairs to his apartment. A very young woman, seemingly in her teens, opened the door.

Answer 1

This is how i would write it:

This is what happened as she found the apartment:

Finding the correct number at last, I slowly climbed the stairs to his apartment. A very young woman, seemingly in her teens, opened the door.

Answer 2

Definitely the period.  I run writing workshops.

Answer 3

A period...im a creative writer and it looks good...the period works fine!=]]]