You don't need drugs to have a good time - period. If it's peer pressure that makes you want to take it - don't.
The problem is that MDMA is illegal almost everywhere. What you actually take may not be pure, there can be other things mixed in with it. You don't know what those are.
Any drug has side effects and MDMA does have side effects. It can cause problems with blood pressure (cardiac).
Hope it helps.
I agree. Taking drugs is not good for anyone. MDMA is also not good for anyone. You can read everywhere about MDMA effects and I bet that it is not pleasant to read all those things. Also, if you have mild heart murmur like you said, it is even more dangerous because MDMA can cause a heart attack as well. And yes, it is illegal and you really don't need it to have a good time.
You are really young and you need to start to live now...if you start to consume illegal things, I am not sure how this can finish for you.
Give up on this idea before it is too late.