Is My Guppy Pregnant

[Cookiekirkwood]

Got four male guppies in Oct!! they were very small, about two weeks ago I noticed one getting a lot bigger ie more rounder and then today it looks lot bigger and puffer. It looks like it's breathing very fast and the other 3 fish are following it constantly. Could it be pregnant?

I've looked for the gravity spot they talk about but can't see it.

Trying to up load a pic but too big.

Thanks for help & advice.