I had discovered a blood blister on my external vaginal area a couple of days ago. I have never had this sort of thing, and my period started a couple of days later. I popped the blister and blood came out, but it still hurts and has been itching a little. I haven't been sexually axtive for about 5 months and have never had this kind of thing before. I am 135 pounds, so I am not overweight. What would cause these blisters? I haven't been kicked in that area, and have not been hurt in that area either.

Thank you,
Suzanne Weiss