I bought a filly last October. She's almost three years old now. I haven't seen her come in heat since the week we bought her. The geldings leave her alone. She doesn't wink or squeal or raise her tail. I thought one of the geldings may have had a retained testicle. I never saw him breed her but just trying through the fence. She doesn't look pregnant at all. Why is she not cycling or is she and I don't notice?