You can be heavily pregnant and not realise it. Cryptic pregnancies aren’t that uncommon, with 1 in 500 not recognised until at least halfway through and 1 in 2,500 not known until labour starts.
100 Mind-Blowing Pregnancies Facts
Some animals can delay their pregnancies. Most carnivores can pause their pregnancies for up to months. Delayed gestation is observed in all bears, most seals, and many rodents, deer, armadillos, and anteaters. Imagine if humans could do that, too.