The Barbados-born singer, 33, revealed her baby bump in a series of images as she strolled through New York with her partner over the weekend - wearing a £5k pink coat.
Despite the cold weather, Rihanna ditched a top under the coat and instead wore a string of pearls and a gemstone cross necklace.
The star, whose hits include Shut Up and Drive and Diamonds, and the rapper, also 33, have known each other for almost a decade, but their relationship turned romantic in 2020.
They paused to kiss and hug as they strolled hand in hand, with A$ap tenderly kissing her head at one point.
Fans speculated that she was pregnant in November of last year, when she reportedly told staff not to smoke around her when she attended Barbados's first presidential inauguration.
Some even claimed to have seen the baby bump.
But she put the rumors to rest the following month, when a fan tweeted her: "Can I come over for the baby shower sister!? This is true whether your kids are going to be beautiful or not. Sorry, everyone's in your uterus right now."
She replied: "Ha! Pause! You haven't been to the first 10 baby showers! You all make me every year damn it lol."