Wiz Khalifa and Amber Rose will be "licensed married" within a few weeks.
The couple got engaged in March this year and announced Amber's pregnancy at the MTV Video Music Awards (VMAs) in September.
They have so far kept quiet on their wedding plans, although Wiz has now confirmed they are planning to tie the knot sooner rather than later.
"We're gonna get, like, licensed marriage, in a couple weeks we'll have that done," the 25-year-old rapper told New York City radio station Hot 97.
Amber, 29, is in her third trimester and the couple are waiting to fully celebrate their union until after she has given birth.
They are planning a big bash with all their loved ones present but want the model-and-singer to be able to enjoy the day properly.
"When you have the ceremony, that's when you can invite the family," Wiz explained. "She can fit into a dress and then like nieces, nephews. If we have a daughter one day, she might wanna give the dress to our daughter, but if she's pregnant then she can't do that."
There is another reason the pair have decided to postpone a raucous celebration. "She wants to get drunk," Wiz laughingly claimed.
The couple are yet to confirm whether they are having a boy or a girl, although they have been thinking about baby names. Wiz previously admitted they have found it hard to settle on monikers, although he is preparing to agree with whatever Amber says as he wants her to be happy.
He is willing to make sacrifices for his fiancée and has also stopped smoking marijuana around her.
"I smoke outside instead of inside. Everything is all about smells, man. If the smell irritates her, then it gotta go," he said.