Hey there,
I started having nose bleeds when i was about 8 weeks it something to do with increased blood flow and your capilleries they stopped a few weeks later.
I also read that its a symptom of second trimester to get a "stuffy" nose and i also have had these "membranes" when ive blown my nose. its gross. I mentioned it to my doctor at last appt and she said not to be too worried and that its common.