Don't stress! As far as I know, when you get an interview invite really varies and has nothing to do with how competitive you are. I received my interview invite really late, about a week before I interviewed. The dates I had to choose from? The very last dates available. I not only made it into the class of 2017, but I'm thriving. Don't worry, just yet 🙂
I finally got my interview confirmation! I hope to make it into the class and thrive like you! Thank you for your words of advice!