AS WE CAN ONLY GUESS WHAT THIS LUMP COULD BE I WOULD SEEK VETANARY ADVICE ASAP.
If it was my cat I would be very worried about a lump of that size
her hormones are are all over the place with being pregnant, and to be honest I would be thinking it ''COULD'' be a mammary tumor
I do not want to alarm you and I hope my ''GUESS'' is wrong but please do seek advice from the VET!
