What causes pale gums?

What causes pale gums, I have noticed only today how pale my gums have gone, I gave blood two weeks ago and had the thumb prick test for anaemia which came back ok and I gave the blood as normal but over the last couple of days my gums really have gone very pale and I have no idea what could have caused it, surely had I been anaemic it would have shown up before giving blood wouldnt it?

What causes pale gums?
Healthy gums are pale pink and stippled....NOT shiny smooth and red. Have you been cleaning your teeth better recently?The part where the gum joins the lip is often VERY pale as there is bone directly underneath. VERY pale gums (as in the part around the teeth) I would have thought if anything would be to do with Anaemia?! But you say you were tested for this? Hmmm! Do you often look at your gums? Could it be that this is a normal colour for you, but you just don't normally look??