I was doing sitting military presses last night and on one rep late into the exercise, I felt something tighten in my right tricep. I dare to say it felt like something rolled around a bit but it definitely did NOT tear where you feel the whole tricep roll up towards the shoulder. I woke up this morning and now I have this huge bruise on my tricep. It doesn't hurt or anything although if I massage the area, it's somewhat sore. What could have happened?