Feeling crappy after basic bloodwork? Do you up-dose iron before or after bloodwork?

I read that donating blood is one way people with too much iron can easily lower iron levels, and have seen some comments here about even basic bloodwork possibly impacting iron levels.

For my current treatment, I think having bloodwork about once a month is a good protocol. I have other tests run along with iron-related tests, so end up giving 10-20 vials each time.

1. Is just 10-20 bloodwork vials enough to make one feel crappier after?

2. Do you updose iron before or after blood tests?