Ohhhh Positive?

Today in my pregnancy class we discussed the problems that occur with the mother being Rh- and giving birth to a baby with Rh+. I got to wondering what I was and I ended up calling the clinic to find out about the blood work done on Thursday. Turns out I have nothing to fear because I was Rh+. During my class we also discussed blood types and I have never found out my blood type. Turns out I have what 40% of the population has. I am O+. We were talking about the likelihood of being RH- depending on blood type and a girl who works as a nurse stated she was O- but she never got a shot to help her out in being Rh-, the professor asked if she was sure she was O negative and the girl assured her she felt positive. I chuckled as this conversation continued. "Are you sure you are negative?" "I'm positive!"