Pregnant rat maybe?

I'm not sure if she's pregnant but she's been with a male for 3 weeks and is getting fatter and her teats are showing but I'm just not sure.

3 weeks is the natural gestation period but he can get her pregnant anytime she's in heat during that time. I assume she's not exposed to the male anymore?
The best way to.determine pregnancy is by recording daily weights. Weigh your girl every day around the same time. The weights can tell you IF a rat is pregnant, and the state or health of the pregnancy. How old is your girl?

I think she's 4 months old

She's been drinking a lot and stashing her food a week after I put the male in then she started getting fatter slowly

I'm really not sure why you put a male in with her to get pregnant when you don't seem to know anything about pregnancy or birth. They could have serious issues during birth, or afterwards and you won't be prepared. We are a rescue based forum and really don't want to see even more rats brought into the world without much forethought.

I have mice but they mostly are feeders for my friends snake but I've never had pregnant rats. I've had pregnant mice and she's my moms. My mom looked at her and what not and confirmed she was pregnant and I'm pretty sure I'm ready for the baby rats I was just asking because I had never had rats but my mom has. Also not all will be fed I'm just more experienced with mice.

I had a rat die giving birth. She was very healthy when it happened, but one of the babies got stuck in the canal, and her contractions stopped, and she bled out. She died of shock. She went into labor some time in the early morning, before I woke up. By the time I found her, it was too late. Also, make sure you separate her from the male NOW! She could give birth, and immediately get pregnant again. Also, sometimes the females get really protective, and can hurt the male, or the male could hurt the babies. Also not sure if you read the stuff about the forum and rules, but this is an animal friendly forum. We don't discuss feeders, or breeding to feed. Many of us have rescued our babies from pet stores that were selling as feeders. Just an FYI.

Ok thanks for that I actually stopped feeding my mice and I'm pretty sure ill be selling the rat babies as pets. I know my mom is keeping one and I'll make sure I'll find homes for them before they're born. My rat is also only 1 week pregnant it just easier to tell if a mouse is pregnant and she hasn't started nesting but I know she pregnant because I can feel the babies

I hope you have a good vet that you can contact day or night and a great deal of money, in case she requires emergency surgery before, during or after giving birth
Babies can only be rehomed in same sex pairs or same sex groups, never alone.

You should not be feeling her belly
Given her appearance she will be soon giving birth
so I hope you have a good vet lined up, a possible foster mother, and are prepared to hand feed every single baby every 2 hrs around the clock for 2 weeks in case mom can't

You do realise that you have endangered her life
That poor baby girl, and those poor mice

This is a rat rescue forum, we do not support the breeding of rats (or any other animal) for any purpose,
and we do not support using animals for food

You are welcome on here but I hope you will read the rules

I want to add, if you can feel her babies, she's more than a week pregnant. Rats hide pregnancies, so they typically don't show until the very end. If you can feel the babies, she will have them in the next day or two. So be prepared.

My mom has owned rats since she was a kid and she said the babies will hid basically in her rib cage and you can't feel the babies that much and we also weighed her and she weighs 266 grams and last week her belly wasn't big also I don't feed the mice anymore I stopped after I found out one of my mice had down syndrome

If I need to hand feed I have kitten milk replacer that I used to hand feed Orphaned baby mice

Usually rats are good moms. It's good you have replace milk and have done it before, but I'd give the mom a couple of hours to see if she's going to take care of them. Baby rats are extremely difficult to take care of, so hopefully she will do her part. It's easy to see if they've eaten, since you can see through their bellies. My older female rat was such a good mommy, that even after her babies were a couple months old, I put an orphaned baby mouse in her cage, and she immediately went into mommy mode, and took care of it. Somehow it fed, and she cleaned it. He lived for a bit with her, until I figured it may not be a good a good idea to keep him in there, and found him a home. But my Mackie is extremely gentle, and loving to every animal we have.....

I'm weighing her every day and right now she weighs 277 grams and can she have her hammock in or should I take it out

Leave it. She won't give birth in it, but she WILL want a place to go to escape the babies here and there. Just add stuff she can use to make a nest, like a toilet paper roll that's got a little bit of paper left on it, some fleece, a couple of tissues, or paper towels, and a small tissue box. Or any small box, maybe from pop tarts, or ziploc bags. Also, nice, clean bedding. If she has hoarded food, leave it there, and make sure you increase her food a little bit, with a good, quality lab block. Once she has the babies, maybe give her a bit of soy baby fórmula, or some baby food meat.

Does this look okay? She's been seeping under the hammock. I also have a heat mat set on low because it really cold.

That looks like a pretty tiny bin
not good imo

Do not give her anything with threads, and give her strips of paper towel for nest building

Make sure she ac move closer or further away from any heat source
make sure she has access to two water sources
remove all levels and hammocks as babies can fall from them if she carries them up there

The bin is only temporary until my mom can afford a cage but she can't because the government is shut down so when my step-dad gets payed she'll by a new big cage and I can't turn on the ac because it is way to cold in my room so I have a heat mat on low. I have sadly lost a rat because it was too cold and I don't want to make the same mistake. And I have just removed the hammocks from her bin and the cage were getting is this one.

Just FYI, in a bin, or closed in cage (not bars) you can't get airflow, and it's easier for them to get respiratory illnesses. I learned the hard way when I first started keeping rats. The cage you posted is perfect. One day I'd like to get one. I have homemade cages right now, but I want to change them up.