If she's not spayed and she's been allowed outside she probably is pregnant.
Are you deliberately trying to breed her? If you allow her to mate with feral cats you are letting her be exposed to FIV, FeLV, Feline Coronavirus, rabies and parasites. It would be much safer if you kept her indoors. Kittens born with these diseases often die quite horrible deaths.
Yes I plan to spay her. She was a barn cat that stole our hearts. She has had all her vaccinations. They are our neighbors males not just feral cats. Although I understand that don’t mean there isn’t some around. I can not keep her indoors she has to have access to the barn etc. I have been trying to keep a close eye to he coming into heat. This is my first cat. Never seen heat in her, she is extremely moody this week won’t let me rub her belly but wants on me 24/7 her tummy is swelling.
Those nipples don't look very pink. She might be pregnant, or might not. However, even if she's not pregnant now, she will be pregnant soon, given your situation. If you do not want kittens, you can make a spay appointment now.
I would suggest getting her spayed asap. Especially since she's moody she might be in heat, keep her INSIDE until she can be spayed or you bring her to the spay and they say she's pregnant. Then you can decide on if you want to keep the kittens or not. Having a litter of kittens is much more expensive than a spay so you will have to decide financially if you can afford it and if you have the time to bottle feed if need be.
Yes, I'd really recommend spaying her now rather than letting her have a litter. Pregnancies and deliveries can be dangerous for a cat and taking care of kittens is so expensive. I cared for 4 orphans for three months and it cost me around $1,000 in food ,cat litter, blood tests and vaccines. They were all lucky enough to have a place in a Cat Café and then a forever home, but it can be very difficult to rehome kittens.
If you want kittens there are plenty looking for new homes in shelters all over the country. Or you could volunteer to foster a family while they wait for their forever home.
Let us know if you need help finding a low cost spay clinic in your area.