The 38-year-old captioned the post, "#PapaBear thank you so very much for choosing me to be your mama."
"Wishing you guys a happy & prosperous New Year," she wrote. "Thank you for your love & support throughout this journey. It’s meant so much to me."
Minaj continued, "Becoming a mom is by far the most fulfilling job I’ve ever taken on."
She added a sweet message to other moms and expectant mothers during coronavirus: "Sending love to all the superhero mothers out there. Big hugs to all the women who have been pregnant during this challenging time."
In a couple of the photos, you can even see her son's "Papa Bear" necklace. Nicki used the sweet nickname in her post, still leaving her followers wondering what his actual name might be.
During an interview with Entertainment Tonight, the rapper revealed that she almost named her son "Ninja" before changing her mind at the last minute.
She said, "You know what his name was supposed to be? I think l might still change it. A lot of people said they liked it, but I said, 'Nah.' His name was going to be Ninja."
"I changed it at the last minute," she explained.
Many celebrities and fans were impressed by the photos.
Kim Kardashian wrote, "beautiful baby boy."
Halsey also commented, "Stopppp I would be squishing 24/7 !!!!! Bless y'all!!"
Big Sean also chimed in, writing, "Sending love to ya family! God Bless y'all!"