Now that Ashanti and Nelly’s secret is officially out, she’s proudly showing off her baby bump! One day after the “Foolish” singer confirmed she and the rapper are expecting their first child together — and are engaged — she took to her Instagram Story to put her pregnant belly on display. In the video, Ashanti, 43, showed off her royal blue sleeveless dress, which hugged her growing bump. The star had her long hair slicked back into a ponytail and wore big statement earrings and a few chunky bracelets. The “Baby” crooner simply captioned her upload: “@nelly❤️🙏🏽.” Ashanti revealed their exciti…