Earlier this year, EastEnders actress Natalie Cassidy announced she was expecting a child with her fiancé Mark Humphrey.

She wrote on Twitter: "Evening all… Time to let everybody know that @cameramarc and I are having a baby in the summer. The three musketeers become four."

The baby will be her second child, as she already has a daughter with ex- fiancé Adam Cottrell.

Another EastEnders actress who is expecting a baby is Kellie Bright – who plays Linda Carter. She announced the news on Twitter, writing: "Shhh… Don't tell anyone, but I'm pregnant! My hubby and I are over the moon & looking forward to meeting our little person in November #Mama @ 40."

Sonia and Linda's pregnancies hadn't been written into their storylines, which seemed fine until last night's episode where fans saw Sonia's baby bump.

And if EastEnders bosses thought that viewers didn't notice, they were definitely wrong. In a scene aired last night, fans pointed out they forgot to conceal Natalie's bump. Many fans took to Twitter to point out the mistake.

One fan wrote: "Sonia is proper showing and they didn't make an attempt to hid it."

Another commented: "I take it #EastEnders are just pretending like Sonia/Natalie Cassidy isn't actually pregnant."

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Some fans appeared to be confused on whether Sonia is pregnant or not.

"Am I missing something, how is Sonia pregnant in EastEnders??"

"Is Sonia pregnant? @Nat_Cassidy #EastEnders."

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And it seems Natalie's belly isn't the only one the show has forgotten to cover up. Fans also pointed out that they've previously seen Kellie's stomach too.

"Thought they were doing a bad job of covering Linda's bump, but Sonia's last night [laughing emoji] surely you can do better than that #EastEnders."

"#EastEnders really are not trying to hide the fact that Sonia and Linda's actresses are heavily pregnant."

"It would appear that #EastEnders are not even trying to hide Sonia & Linda's large baby bumps #NoBigHandBags."

Did you notice the mistake?

Have you ever noticed EastEnders or another soap fail to conceal a baby bump in the past?

Let us know on Facebook or Twitter (@CloserOnline).