Translation:Your mother was giving birth to you, when I took this picture.
The correct translation is "Your mother was giving birth to you when I HAD TAKEN this picture" . it is in the past perfect tense, therefore TOOK becomes HAD TAKEN. source : http://www.englishpage.com/verbpage/pastperfect.html
Jeg tog et billede = I took a picture
Jeg havde taget et billede = I had taken a picture