Should I go see a doctor?

I am currently 15 years old and a girl. This year, I have been feeling weird. At times, it would get a tiny bit tougher to breath. Like, I could still breath, but it would take a little more effort to do so. Also, I randomly get pains around my heart. It'll just hurt in my chest and I always would say "Heart Burn", but I don't think it's that. They usually happen when I laugh too much, or if I cry a lot, or after I smoke. I've recently gotten into smoking weed, but I barely do it. I have only done it about 4 times and they were separated between months of like 2 months each time. Occasionally, I would smoke cigarettes, but I don't do them anymore. Also, sometimes when it would get a little tougher to breath, my pulse would start to become very strong... So strong, that I could sit perfectly still and my body would move just a tiny bit because of how strong my pulse was going. I used to get pains in my body also... usually found the pains are in different parts of my torso, but you can tell they are inside. Not outside. Is there something wrong? I'm kinda scared that there could be something possibly wrong with me.