I had a random patch of bruises pop up behind my left knee, & they popped up within minutes of them not being there. They disappeared two days later, & this was 2 weeks ago, but just yesterday the same exact pattern of bruises popped up on the opposite leg in the same exact place behind my right knee. When I say same exact pattern, I mean both times it was literally four large circular bruises clustered near each other then later, a fifth would pop up to make a circle. & both times, this happened in this exact pattern.