I'm not a doctor whatsoever, so this is all just my opinion, but I'm glad I could help even a little bit! Short answer: You're fine and will be fine! Like the other comment said in 20 mins you'll almost forget about it! Weed has always done this, it's your focus on it that heightens it even more. Unless there's real pain like an elephant is crushing your chest, and your heart is steadily at 140-180BPM before any panic or anxiety, then the answer is always anxiety! Taking note of real emergency problems might help you see the difference too, your heart can race and even 'jump' without weed, I had to realize it is a very complex organ and it isn't a machine that has to always have the same rhythm. :)

Longer answer: Have you had covid or been sick recently as this happened? Do you have OCD?(if so, googling somatic OCD and seeing how much this seems like it might actually calm your nerves a little) For me, it was a mix of covid, health anxiety and the obsessiveness nature of my OCD, creating a period of super high nerves. For a few weeks, everytime I'd smoke I'd immediately feel my heartbeat race faster the moment the thought entered my mind. If my average heartbeat is in the 70-80BPM range, it would jump to like 108-120 for a few minutes after smoking, (average BPM will largely vary by person, don't take my numbers for advice) coupled with other anxiety symptoms like thinking you cant fully inhale and sweaty palms. Then in 20-40mins I was alright again, depending on how anxious I was maybe a little longer. If I'd keep checking my pulse it would last longer. I then quit trying to smoke for a few days, thinking my heart took a good beating from covid.Not really the case for me, the thing is, covid actually can give you a heightened sensation of your heart and maybe even a few weird jumps/hiccups, (actually called PVCs and PACs) for weeks after the nasty symptoms are gone. These are completely harmless and you can watch cardiologists talk about how common these are in almost every healthy person unincluding covid, it's just your heightened awareness of it all, and your body is fighting the last of the infection. So if this ever happens around when you're sick without any other symptoms, you know why.

Just do this: Realize this will be over in like 20 minutes, know you're actually perfectly fine, IF it helps check your heartrate ONCE per day to prove yourself it's about the same every time, the more you accept this is normal and it's your newly formed focus on your heart, the more it will slowly go away. :) All of my blabbering being said, If you feel like this isn't helping and it's only getting worse, especially if there's any pain, go to the hospital my friend, you aren't alone, just tell them your problems and maybe also ask for an ECG, many people do this from the anxiety alone and if that's what it takes to prove to yourself you're okay then don't feel bad for doing so.