Could a cold being reducing my supply?

[Andromaca]

Both me and my DD are having a very nasty cold now. She is not feeding as usual but less and more often. I usually don't have supply issues (I am a milk donor at my local milk bank so I know that I have a lot of milk) but since yesterday when I express almost nothing is coming off.
Could it be that the cold is affecting my supply. I'm not taking any medication for the cold because I hate medicine.

Only if you're noticeably dehydrated (I reckon, am not an expert).
She probably wants more to drink right now -- just like you or I would when we feel grotty with a cold. Hence why she's feeding little and often, and you can't express so much off.

I've often noticed a drop in supply when ill. Not sure if started periods again as that also affects my supply too.

Keep up the fluids and eat oats, it's always helped me.