No this is perfectly normal.
Your body's seminal vesicles and prostate have limited amount of secretions to provide for ejaculation and have to build up more over time which is why you're limited to that number.
The spacing out of them is normal physiology called refractory period.
That your body needs the arousing stimulus to cease for a while and your body get back to baseline (reset itself if you will) before any further stimulation can produce an erection.
Totally normal what you described.
Did I answer your question to satisfaction?
Even the speed of ejection is normal? I read somewhere that it can be 40 miles per hour.
No you're perfectly within the normal range of things.