My cat only has 1 testicle

May naka-experience na ba nito? Kakagaling ko lang sa vet to have my 11 month old cat neutered. After the surgery, sabi ng vet isa lang daw ang testicle niya which is according to her hindi naman daw unusual. Here's the problem: cat may still show signs of heat kasi baka nasa stomach daw yung isang testicle at hindi pa bumababa (or hindi na bababa). The later case will require major surgery daw. This is stressing me out kasi nung in heat yung pusa ko halos lahat iniihian niya pati ako (sa mukha pa). Sobrang sakit sa ulo tapos ngayon hindi pa din pala mawawala yon, and worst, he needs major surgery pa. I don't think I can afford that. I love this cat don't get me wrong. Na-stress lang ako sobra sa situation na to.

May naka-encounter na ba ng ganitong case? If yes, ano nangyari?