I find once I step outside my normal routine it can be a crap shoot, especially in the morning; it sometimes takes the whole day to get back on track.
Everyone has their own body clock (circadian rhythms) and sometimes our body knows its routine better than we do. Maybe your body thought the coffee was the start of your regular eating routine but with no breaky following it, your BGL dropped. (I don't take BP meds so, I'm not familiar with how they work.).
So many interesting things to read about
circadian rhythms. Here's just a snippet from WikiPedia...
Outside the "master clock":
More-or-less independent circadian rhythms are found in many organs and cells in the body outside the suprachiasmatic nuclei (SCN), the "master clock". These clocks, called peripheral oscillators, are found in the oesophagus, lungs, liver, pancreas, spleen, thymus, and the skin. Though oscillators in the skin respond to light, a systemic influence has not been proven so far. There is also some evidence that the olfactory bulb and prostate may experience oscillations when cultured, suggesting that these structures may also be weak oscillators.
Furthermore, liver cells, for example, appear to respond to feeding rather than to light. Cells from many parts of the body appear to have freerunning rhythms.
Hmmmm... liver, pancreas, endocrine glands... I'm usually fond of blaming the liver for most of the loops diabetes throws at us. (I knew it had a mind of its own
- Phishbowl (Type 1 since Jan'05 - Levemir, NovoRapid)
"What's Not Measured Is Not Managed"
"It is impossible for a man to learn what he thinks he already knows"-Epictetus