Sources close to the couple tell TMZ ... the "Love & Hip Hop Atlanta" stars are ecstatic about expecting their second kid together. We're told Bambi is currently around 18 weeks pregnant but they don't know the gender just yet. It's still a tad bit too early to tell.

But, the celebration's most certainly underway. Lil Scrappy and Bambi -- who got married in September 2017 -- are overjoyed and excited to add to the family. They had their first baby together in September 2018 ... 1-year-old son Breland.

This will be Scrappy's third child. He has a daughter, Emani, from a previous relationship.