2 year old pregnant or Was pregnant?

Question
I just got my first horse 3 weeks ago, a approx. 2 year old TB mare.  She's staying at my riding instructors farm.  When we first got her she had long teets and baggy udders, since then they have gone down slightly, we had her palpated and the vet said she wasnt carrying a foal. Yesterday my instructor & trainer squeezed a solid stream of milk out of her teets.  She is right at 24 months old and wasnt in the best condition when we got her.  My question(s) is/are:  What is more likely, that she had a foal and aborted it, or foaled, or could it be horomonal?
If she did have a foal she would have had to have been bred at 12 months (if thats possible) and if she aborted is it possible that she could have been bred back when she came into heat again and it caused her to still be milky?

Answer
Hi Kassidy,
                            I would bring your filly to the vet right away. Have her checked both with an ultrasound and by having blood work done. There can be many reasons for her condition, ranging from hormonal to a cyst in her Uterus.

Lisa