During the day I just drop off in a sleep for 3-4 minutes then wake up. What is this called?

Maybe narcolepsy. If you are falling asleep unexpectedly, could be narcolepsy. Narcoleptic symptoms can also be part of other problems such as obstructive sleep apnea or sleep deprivation from other causes. If you are getting enough hours of sleep, best to get checked; obstructive sleep apnea has a multitude of preventable bad effects over time.
Concerning. I say its concerning. You may have a sleep disorder such as narcolepsy or sleep apnea. Before you have an accident you need to see a sleep specialist for an evaluation.