"Vince and I [were] told we were going to have fertility problems — it was a lot of information — so we had to get comfortable with the fact that it happened on its own," Braxton, 35, tells PEOPLE.
"We decided [not to announce the pregnancy] until we were both really okay with it — that's why we waited."
The memorable moment they found out their first child was on the way is one Braxton won't ever forget.
"I just burst out laughing," she recalls. "It's like, 'What you talkin' about, boo?'"
But now that the world knows, Braxton — who's craving potato chips and cheddar cheese — is being bombarded with "unsolicited advice" — especially from her mother as well as her sister Toni.
"My sisters are making me feel more maternal because they're crazy. They're giving me advice on how to be a mother and be pregnant," the mom-to-be says. "They always have a comment about my shoes, what am I wearing, what am I eating, you need to put your feet up and I'm just like, 'I'm fine!' They're too much."