Just discovered a painless, non itchy very dark red spot/lump type of thing on outside of labia. I thought that all of the STD tests done in early pregnancy would detect if I had anything, so really not sure what this is. Worried, as 37 weeks pregnant. Has anyone else had anything like this? Not sure if it's a blood blister - it's right on the line where my (now slightly too tight g-string rubs a bit).