As anything, if concerned, I would mention this to you OB. But again, from what I have read,
nosebleeds are common in
pregnancy. Below if from Babycenter on Nosebleeds.
http://www.babycenter.com/0_nosebleeds-during-pregnancy_255.bc
"Pregnancy can cause the blood vessels in your nose to expand, and your increased blood supply puts more pressure on those delicate vessels, causing them to rupture more easily.