Hi Jerome!

Yes, it is certainly possible for a person's blood sugar to drop too low even if they aren't taking medication as you just recently discovered. At least it's possible for it to drop low enough for you to start feeling hypoglycemic or uncomfortable. It would be extremely rare for a person who is not taking medication to have their blood sugar drop low enough to put them in physical danger.
Since your blood sugars were normal yesterday and this morning were too low, a question that you need to ask yourself is what is the difference between yesterday and today? What did you eat (or not eat) last night that would have caused a low reading this morning? How long was it since you had last eaten and what did that last meal consist of?
I have had my blood sugar drop into the 60's without medication, but usually when that happens, it has been too long since I last ate or I have been too actively physically with not enough food at my last meal or a combination of the two.
I've also had it happen when I've had a high carb cheat one day and then went back to low carb the next. This is just a guess, but I think my body was producing insulin the next day thinking that it was going to get the same amount of carbs it did the day before and "overshot" on the insulin production causing me to go hypo. Sort of an "aha! I remember how much sugar I got at that last meal, so I'm going to beat you to the punch and produce extra insulin this time around to keep the blood sugar more stable this time". Of course, I could be completely wrong about that, but it's one possible explanation for what happened in my case.
Just some things to consider...