Odd low

Saturday evening, I had an odd incident. From about 5 to 6 pm, we had dinner in with friends at a Chinese buffet we all love. I had a balanced meal even without salad, but did overindulge a bit with desert. It is an over two-hour drive home from where we spent the weekend. Less than half an hour from home, I started feeling nauseous. When I got home, I tested to be sure I was okay from the indulgence, even though I usually set my phone alarm to test at about an hour after I have a large meal like I did that night.
My BG was 61 (at 8:22pm). Figuring I did something weird, I checked it again immediately: 56. Pulled out my other meter (AC Aviva): 70-something. Drank a glass of skim milk & had some peanut butter. Back to the OTMini at 9:15pm: 73. I didn’t feel any symptoms normally stated for a low; only the nausea. I was afraid to go on to bed though, so I stayed up about an hour to be sure I felt okay. Husband was awake in the living room and I lay on the couch. Finally go up to go to bed about 10pm. Forgot to test before I did, also forgot until 3:30 next day (107). Still have no idea what was going on.