Is it possible my spayed feral rescue cat is pregnant?

[SimLondon]

So I have a cat that came to me as a 4/5 month old kitten from a feral rescue society on the grounds that she was spayed. The rescue society felt that she was to much of a feral to ever tame up and wanted her to have an outdoor/barn cat life.

A year on she is still a timid cat, spends around 16 hours a day indoors (in my house) will happily rub up against you but does not like you touching her.

Her body shape has erm changed noticeably in the last few days her stomach - the back half has got quite large, I thought someone else was feeding her - we always make sure she has good quality biscuits in a couple of places and feed her wet food once or twice a day as well.

I'm now wondering if she could be pregnant? could the spaying not have worked? I was planning to worm them this week but don't want to if it's not advisable for pregnant cats?

If she is pregnant then does anyone know the gestation period? I don't want her wondering off somewhere next door to give birth and would keep her in if she is about to give birth.

When you got her did she show signs of having been spayed? (Shaved patch etc.)

Otherwise, I guess it depends how much you trust the rescue to have been both honest and reasonably together.

I'd get her to the vets to check.

As cozie has said I'd she have a shaved patch. Usually when neutering feral cats which put a nick in one ear so we know that have been done.
If she has been spayed both uterus and ovaries have been removed so no it can't fail.

Ah yes average gestation is 63 days range is 57 to 72. If she is pregnant scan can give you a good idea of how far along.

She has the nick in the ear - so that means she's been done? and it can't have failed?

I don't think she would be comfortable with a scan :-) I wonder if something else is causing the extended belly and i should worm and if that doesn't work take her to the vets.