My cat was in heat as several cats have been hanging around. The cats have stopped lurking and my cat has spent the whole day asleep, she is also off her food. I s this a sign she may be pregnant?

Well outside cats can lurk around even if she is inside and in heat. Sometimes my cats do sleep literally the whole day too. Why is she off her food. I would think if she is pregnant she might be a little more hungry then usual. Cats can get pregnant at 6 months old that's why it is good to get them fixed. If I were you I would wait now and make sure she is not pregnant before you get her fixed, that is if you intend to. So did she get outside? Is her stomach getting a little hard? If she is you may not be able to tell so quick on. A cats gestation period usually last for 63-65 days, so a little over 2 months. If she is pregnant you will filll her stomach start to get a little harder. Hope this has helped.

You can pretty much bet that if the cat has been in heat and has had access to males, she is pregnant. They are the most fertile creatures on the face of the earth. You should be able to have her spayed during early pregnancy, and don't go on a guilt trip about it. If there are embryos present, they are very tiny and will never know hunger, cold or cruelty.
In spite of best efforts it is hard to find enough good homes for a litter of kittens this time of year.