Help ! My 13 month old cat gave birth to One kittten

 Sometime yesterday I am not quite sure when my cat gave birth to a single kitten. The thing is I did not even know she was even pregnant, yes we have two male cats, one a few months old  that we adopted at the pound and I know is neutered.  The other  a litter mate, which is the father ( is not neutered ), because she is an exclusive indoor cat, as are the other two and would not dream of ever going outside I can be certain he is the father.

  Anyhow , so yesterday morning just like any other morning for the last year I feed her,she ate and did her business, but since yesterday I was going to be gone most of the day I put her in her travel carrier with food and water that she hold her over until I came back. I came back several hours later, to let her out  to stretch her legs and use the litter box. She meowed a greeting to me and headed to the litter box, when I looked in the carrier I saw a small grayish thing, at first I thought maybe a hairball (FYI she has never had a hairball) as I looked closer and saw that it was moving, I realized it was a newborn kitten, there was no blood  or any kind of mess of any sort, just this kitten and a very clean carrier.

  In my opinion she did not look pregnant at all, she did not  have a belly or anything, but almost 24 hour  from the time of discovering this kitten my cat now looks pregnant, I am worried that maybe she is still pregnant or has some stillborn kittens left in her or the placenta  (since I was not there when she delivered this kitten I do not know if it ever came out or if it did and she ate it.

  My cat is her normal self she is eating and drinking and using the bathroom as normal, but she just looks pregnant and I am scared something maybe wrong especially after reading all this stuff on the internet which may or may not be true or accurate, no vets in my area are open because it is Sunday and I do not know what to do. I am hoping to just watch her tonight and call a vet  tomorrow no matter what. I do not know how normal this is because I am new to cat ownership even though  I have had her since she was a little over a month old.

Keep the intact male away from her---cats can get pregnant again very quickly after giving birth and you don't want this happening again! Don't let them be together again until at least one is fixed. If he's fixed first, give it a week or so after he's neutered before letting them be together because sperm can hide in the tubes for a little while. Hopefully the kitten will not have any problems from being inbred :/.

It's not too unusual for a cats first litter to have only one or two kittens, but to be sure, have the vet check her out to make sure. If she seems calm and not in pain, it's not an emergency and can wait until tomorrow. But definitely get her in tomorrow.

 Thanks, they are usually kept apart and yes I am aware that a cat's first litter is usually small and all that info that goes along with neutering the male and aftermath, etc. My main concern was the female still looked pregnant and if she still had kittens inside particularly stillborn ones  or she did not deliver the placenta of the first kitten. She in fact gave birth to another kitten this morning, but looked even more pregnant today then yesterday.

Hmm. A few hours between kittens is not unusual but a whole day is a little odd, especially if you think there are more. Are both kittens alive and healthy, nursing well? If she doesn't seem to be in distress that usually means everything is OK but if there are any dead kittens in there that won't come out the sepsis could kill her. The only way to really know is have the vet do an x-ray or ultrasound, or have him give a pitocin shot to clear the uterus.

Yeah I have heard that, in fact the cat I speak of was the last born of her litter a year ago and she was born like 2 or 3 hours at the rest so I know that is not all that unusual. Actually it was two days, the first kitten was born sometime on Saturday and the second one was born about 7am yesterday morning. Both kittens are alive and appear healthy and she is nursing them and loving on them. She is pretty much back to her normal self, she is eating well and using the bathroom, I believe she looks less pregnant than she did before.She did not look pregnant at all until after she had the first one  on Saturday and  looked even more pregnant on sunday and then Monday morning she gave birth to the second one. She has appeared fine after and even in between the births of her two kittens. So when I get home I will have my sister look into  that.