Weak heartbeat/stress?

Hello my names Miguel, im 17. Recently sometimes after exercise when i try to check my pulse it feels weak or non existent. I have a cardiologist, i have a slight arrhythmia but after taking tests ranging from MRI to stress tests she has said i have nothing to worry about. Im also a hypochondriac and i worry a lot about my health. Yet, i have learned how to get over my symptoms and live a normal life. But this is feels different and im not sure how to go about it. I live a fairly active lifestyle, i play soccer almost all year and I'm used to pushing my body. But because of this weak pulse its starting to freak me out. What should i do, or do you think its just another trick my brain is playing on me? Help please

Weak heartbeat/stress?home theater

First off, Steve is a douche.

Secondly, its probably nothing, especially if youve already been checked out. If you didnt die from it the first time you probably wont. People feel their pulses differently and they can vary, especially if you are 17.