"Do you know if its boys or girls yet?" one fan queried.
While the newly-engaged couple stayed tight-lipped, many fans in the replies suggested that, from their experience, they believed Melissa was having at least one girl.
"One is 100% a girl going by the sonogram ❤️❤️," a fan suggested.
"I think I see a little girl in there if I go on the nub theory from when I was pregnant!!!!" another added of the nub theory, which examines the genital tubercle, which can be spotted on the lower abdomen of babies. The tubercle or "nub" will either turn into a penis or a clitoris. Many believe if you study the way the nub is growing in the 12-week scan, you can figure out the gender.
"I have had four girls and I'm pretty sure I saw girls too ❤️ Either way, so special, congratulations guys you are blessed ❤❤" a third wrote.
Meanwhile, other fans were more determined to find out whether the twins were identical or fraternal.
"Congratulations - are they identical or non identical? X," a follower asked.
Another fan was quick to reply, writing, "identical same sac".
And others certainly echoed this sentiment.
"Ohhh cute are they identical? Looked like they were in the same sack :))," one wrote.
"Ahhh nice one! They are in the same sac hey !," a second added.
WATCH: EXCLUSIVE: MAFS' Bryce and Melissa announce twins and engagement (Article continues after video)
Of course, this is all just speculation and we won't know for sure until Melissa and Bryce confirm it themselves.
The couple exclusively told New Idea they were engaged and expecting twins earlier this month.
“It’s all happened very fast,” Bryce admitted to us at the time.
“It’s been a whirlwind, but we’re so incredibly happy,” added Mel, who pointed out that their twins will be a world first for the TV franchise.
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