Vida has a lump

If you look at this picture its on her off side about where the uterine horn is at in the above photo. Its a little smaller than a golf ball and she acts like it doesn't hurt when I palpate it.
She has been acting like she may be going through her first season of the year. Do you suppose it could be a egg in the uterus getting ready to be sloughed? At first I thought it might be an ovary but its a bit further back.
She has been pooping and peeing regular and acts fine.
We plan on having the vet out this next week for everyones vaccination but wondered if its something that I should even be worried about.
I used to get ovarian cysts that could be seen and felt on the outside of my skin and I didn't know if horses were anything like humans.

With this better picture it is very much where the ovary's are. Any thought, are they that close to the surface that you can feel them?

No idea here, but good luck.

I've started the process of turning them out onto pasture grass last week. I do it gradually over a week or 2. I wonder if that has something to do with it.
I'm hoping it goes away before the vet comes I want to be nothing so badly

Maybe its just a reaction to a bug bite if she's been going out on the grass.
I too hope its nothing Maureen.

It's not likely that it's from a egg about to mature. It could be from an injury, reaction to an insect bite or even a mass. If it doesn't go away in a day or two or it becomes painful or she shows any other sign of a problem, have the vet out for an exam.

I was so hoping you would read this Ryle
The Vet is coming this week anyway for shots. Its been there for 3 days now, I'm really trying to not freak out to much. I'll be going out to bring her in from the pasture in about an hour I'll check her again.
It doesn't feel like a insect bite but I never thought of it being an injury. I'll hope that's what it is and not some internal mass on an organ.
I have some DMSO should I put some on it?

Ok I just came in from feeding. I gave it a good hard pressure feel (while Tony held her ) It does almost feel like its in a hoof tip shape. I put some DMSO on it and will check her again in a few hours.

Could be somewhere along the lines of a hematoma.

I'm thinking that's what it is now. Phew I was really worried. I'll still have the vet have a look but I'm not near as worried now.
She didn't like the DMSO at first, she kept licking at it (I think it kind of burns) but when I just went to check her again she's fine.