How do I know that my cats pregnant?

She's had her spayed and it acually looks like she's pregnant and I've gone onto the internet and serched up how to tell if your cat is pregnant and it came up with some things like 2 cheek her nipples and if they go swollen and pinker than they are now then she's pregnant and there's more she goes outside A lot so I don't know what to do

Please help me.

When a cat is spayed,all of her equipment is taken out. It possible that she might be going through a false pregnancy, retaining water, or gaining weight. To make you feel better take her to the vet.