Hmm, the FIRST time I got stoned I had a similar experience. I was like eh, 14? And my mom and dad were home and me and my friend got high and I was chill and laughing then I was like "I dont want to be a stereotype stoner who laughs at everything, fuck that" so I just told my friend be quiet and let me watch tv. So we chilled and then I got all nervous I was like "My parents know dude, I can tell." Went and took a shower and then I just chilled for a while. But yeah, I could feel my pulse then if I moved it'd stop for a bit then come back.