I believe someone has stolen this vector you made along with other vectors from others (including one of my own O.C.) and I thought you might want to know since the O.C. owner has already been notified. swirlycakes.tumblr.com/
I do all of my vectors with Ponyscape, which is a modified version of Inkscape (free) made for Pony artists. There are a lot of tutorials on how to create vectors, here are some for example: [link] and [link]
I hope this helps! If you have more questions, feel free to ask!