I don't know what it will cost there but here a call fee is about $75. If they have a portable ultrasound machine they can do that if you want. I don't know what that will cost you but they can tell you before they come out. Most mixed practices have them for preg checking cows. It's a very good idea to have a vet anyway for who knows what happening.You will probably be told something like, Well, she doesn't look it/very big, maybe more of an answer with the ultrasound. This is just my opinion but I would find a vet since you should have one anyway and have their number on hand and your name in their system in case you need them. You've been feeling kicks. I'd go with she's pregnant. Use your money to fix up her stall and get a camera up, get her and Arrow in at night so she's VERY comfortable in there if she foals and with you handling her. Put together a foaling kit and a couple of very warm foal blankets and try to figure out a heat source for in the stall/barn. Go with she's in foal and try not to be too disappointed if it turns out she isn't. You want another mare to have a foal at some point anyway so anything you do will be used then if she doesn't have a foal. This is going to make you crazy no matter what, keep feeling/looking for foal movement and trust yourself when you find it. As far as I know the only way to know for sure is an internal ultrasound/palpation which isn't a great idea with these little ones. If you take pictures one a week instead of every day you will have a better chance of seeing any changes. Are they up to date on worming? If not I'd give them a dose of ivermectin.