If Megan Fox is actually pregnant she has the slowest gestation period of any mammal on earth and will end up giving birth four years after conception like an African rhino or Jessica Simpson. (Seriously, chick was pregnant forever, right?)
Rumors that Megan is knocked up have been circulating since March, but the actress continues to get papped with nary a baby bump visible. That said, it does look like Brian Austin Green is covering something up here. It also looks like he's pulling a ten foot pole from his a*s, but maybe that's just his usual facial expression.
Anyway, Megan hasn't come out and said that she's not pregnant, so it's possible, even likely that she is. As for why she's over four months along and not showing – well, my best guess is that Megan has discovered a way to make her unborn baby binge and purge.