It ached a small bit.
I noticed the ache when I leaned up against the kitchen counter to grab a mug from the top shelf for my tea. Not a holy-crap-that-hurts sort of feeling, but more of a latent bee sting. It didn't feel right and I knew it would be painful once I focused on it, so I pushed the pain out of my mind and instead reverted my attention to the tea.
I tested: 180 mg/dl. Bolused half a unit to bring me down.
An hour later, I tested again: 186 mg/dl. That bolus did nothing? Didn't seem right.
Waiting for the shower to heat up and planning to change my infusion set afterwards, I pulled out my site. Immediately after I pulled the plastic away, a drop of blood seeped up and scurried down my thigh. The cannula revealed its vampiristic tendencies:
This explained the dull ache at my site location. It also explained the fact that a 1/2 u of Humalog fell into some kind of useless void.
No problem. Changed the infusion set, laced in another half unit to correct the high, and slid a garter of garlic around my thigh.
When it comes to these vampire cannulas, you can't be too careful.