Empath?

I'm 15, and I live in England. I was pretty skeptical about this stuff, but I'm starting to wonder whether I am an Empath.

Of course, being a 15 year old teenage girl, I assumed that mood swings were part of normal teenage life. Every now and again I'd get waves of sadness, and then waves of happiness, within minutes of each other. I thought this was normal, until something really caught my attention.

It started as I walked into the cafeteria. As soon as I stepped through the door way, I was angry. Like, so angry my fists were shaking with rage and I had no idea why. I'm generally not an angry person. I had no idea where any of this had come from. I'd been absolutely fine just minutes before! As we walked into the food hall and sat down, my friends noticed I was distressed, and asked whether I was okay. I told them I felt angry and I had no idea why. Then, moments later, a guy a year younger than me leaped across his table and punched another boy in the face, and a fight ensued. We left the dinner hall soon after this, and as we walked away from the fight. I felt myself become calmer and calmer, as if the emotion was becoming weaker and weaker.

Some time after this, another event occurred with my friend. She seemed fine all morning, but I knew there was something not quite right about her. In chemistry, I went over to collect a worksheet, and suddenly felt like I was going to cry, I was so sad, and again, had no idea why. I turned around to find that my friend had just burst out crying. Turns out her dog died last night, she'd just kept very quiet about the whole thing (shes not one to look for attention)

I've had many other incidences like these over the past year or so, and these waves of emotion are really starting to mess me up. I find it hard to concentrate and relax, because somehow, somewhere, wherever I am, there are other people with their own problems. I'm also starting to wonder whether I am normal, or whether I am being a bit over-dramatic about the whole thing, and it's all a figment of my imagination. Please comment if you have experienced anything like this at all, it would really help.

Is this a coincidence? Mood swings? Empathy? Or just good at reading situations and people?