GISELE UMMMM ... PREGNANT??

Can't ignore the obvious ... Gisele Bundchen had a pretty obvious bump during a modeling shoot in Brazil earlier this month -- begging the question ... preggo???

Gisele and Tom Brady were extra touchy-feely during a DeflateGate vacation to Italy back in September ... back when G's belly was its typical flat self. 

So, could baby #3 be on the way for the 36-year-old supermodel ... or was it just a big lunch?