I got the J&J shot in March....had no intention on taking it but family wedding coming up and felt pressured to do so. Anyway, I play alot of golf and walk. Seems all spring and summer and still to this day I get fluttering in my upper chest every now and then. Never had it before...I’ll be damned if I get the booster after this. Hasn’t slowed me down but the episodes are noticeable enough.