Blac Chyna's suspicions about YBN Almighty Jay cheating on her are inaccurate ... at least when it comes to his ex-GF, turned baby mama.
As you probably know ... BC dumped her 19-year-old piece earlier this summer, because she was fed up with YBN sliding into different chicks' DMs and possibly having a side piece.
His announcement over the weekend that he now has a new baby boy -- SirLucius Edward Scott-Bradley -- might seem to confirm her fears, but we're told the baby making went down before Chyna was in the picture.
Sources connected to YBN and the baby's mama, Dailyn Scott, tell us they met when she was working as a stylist for one of his music videos. We're told he knocked her up around December ... almost 2 months before he officially started dating BC, who was aware YBN was going to be a daddy soon.
SirLucius was born on September 4 at Cedars-Sinai in L.A. -- so the December conception tracks.
Almighty Jay was touring in Europe when the kid was born, but we're told he's been around ever since ... supporting the kid financially and seeing him as much as possible.