Is her tummy swollen too? Probably pregnant!
My Cat's Nipples Are Swollen... Is It Possible Its Because Of The Heat, Or Is She Pregnant?
It is possible your cat is pregnant if she was in heat around 60 days ago. Gestation (pregnancy) lasts 59-70 days. Mammary development does occur in the time before birth. Nipples can become swollen during heat--this is likely if your cat is experiencing other signs of heat.