After Taking Mdma Pills I Get Random Sharp Pains In

After taking mdma pills i get random sharp pains in my chest/heart like my heart is under alot of stress, do you know why it does this and should i be concerned?
Also iam starting to go rave alot more often now and iam starting to use mdma alot more now, i probably take pills/ mdma once a week now on the weekends, how bad is this for my health is it really serious ?