Jennie Garth was mistakenly told she was pregnant as teenager in front of her mother

Speaking to her ex-husband Peter Facinelli's daughter Fiona, 18, on her I Choose Me podcast, Jennie said: "My mom went in there and it was to go on birth control.

"I had a boyfriend and I just wanted to be safe. I didn't want to have a baby without being ready for it."

The What I Like About You star - who confirmed the partner at the time wasn't her Twilight actor ex - explained her mother didn't know she was having sex at the time, so she claimed she wanted to "explore birth control options" to help with an irregular period.

She added: "I took a urine test. We're sitting in this clinician's office and they come in the room.

"My mom and I are just waiting for what she's gonna say, and she says, 'Well, you're pregnant.'

"I was like, 'What?' All of a sudden, the cat was out of the bag. I was instantly just red all over. I was hot, sweaty.

"I didn't know what to do because I had, in that moment, to be honest with my mom in the most uncomfortable situation about the fact that I had already had sex and that I had been lying to her about it."

The Beverly Hills, 90210 star revealed the doctor soon realised they'd accidentally read the results from "someone else's urine test", but it was too late.

She said: "Cut to me and my mom having this emotional breakdown... Then she came back in, 'Oh, oops! That was not your pee, that was someone else's pee.' "

Jennie was "furious" over the mixup, but it prompted a conversation with her mother that she'd been dreading.

She added: "That was a lot more traumatic and dramatic than if I had just gone to her and talked to her about it.

"But I, too, was really scared to talk to my mom about it, to the point where I actually lied and hid the truth from her."