Cardiophobia - requesting tests a thing?

First time posting here, but I’m new to this anxiety thing. Started having a massive bout when I got a pinched nerve in my left arm, which it being my left arm lead to anxiety about heart issues. After an ER trip, 3 EKGs, a hotler monitor for 2 weeks, basic blood work, i was told everything is normal (no family history of anything, late 20s, workout regularly) only some mild PVCs. This made me feel back to normal for a few weeks. However, I have been getting these feelings where it feels like my heart skips a beat for a second and mid breath I lose my breath for a second. This usually sends me into a panic. I do have bad acid reflux so I tell myself that’s it and I calm down. Today, I started the couch to 5k program again and on my 6th stint of running I got a sense of impending doom that stopped when I started walking again (no change in heart rate). Kind of sent me completely back. And when it’s back, I just stop working out or physically exerting myself out of fear.

I’ve kind of come up with just straight up asking the cardiologist for an echo as a “this is the last thing they haven’t done”. Is this a thing? I’m sure I’ll look like “that guy” but can you just request a test like that even if they think you’re fine?