The 21-year-old star and rugby star boyfriend were packing homeware goods into their car when Church went into labour.
But her trip to the hospital was delayed.
She recalls, "He'd accidentally locked me in the car and the alarm was going off, so people were coming out of (the store) hearing the alarm and looking at the car, and then seeing it's Charlotte Church in there!
"I was just trying to hide but couldn't - just sitting there having contractions!"
Source: WENN