unwell burmese cat

Question
My cat is 10 months old.  Two weeks ago she came on heat for the first time and i took her to the breeder I got her from to mate with a burmese. She was fine when we got her back from the breeder - obviously we don't know yet whether she is pregnant yet.  We plan to have one litter than get her desexed.  Yesterday she became unwell and is just lying around, not eating, not purring, not interested in much.  She is normally extremely affectionate but i'm not sure what is wrong and am worried.

Answer
Cats certainly can experience nausea and lethargy when they start undergoing hormonal changes associated with pregnancy.  However, these symptoms are also general signs of illness.  So I would urge a vet visit.  Though it's probably too early for the vet to detect a pregnancy at this point, too, her abdomen should be palpated and her vital signs taken.  If any of these is abnormal, it may be wise to put her on antibiotics or perform further testing, such as x-rays or blood tests, depending on what appears abnormal.