I watch my mares and they seem to fill out all the way around starting in about 7th month. As time goes, baby just seems to lie in bottom and the round out underneath. They say that the left side will stick out furtherest. I am not a fan of vet checking, have, but just wait and see in most cases. Has this pony shown a heat? Some mares really become mellow when pregnant and other become such grouches. How long have you had her? Has her dispostion changed? Vidaloco, your vet is so reasonable. I have a $75 stop charge emergincies are more. This vet comes 50 miles, local vets are charging at least $40 and then they charge for a mandatory physical fee, and they listen to heart, lung, and check teeth in which they are so incompetant, that is why I use vet from further away, and they have far more horse sense than our local vets because they do way more horse calls!