Pregnant for 10 months

My best friends sister is about a week and a half behind me in our pregnancy. I told her yesterday that she was almost 8 months and she told me she wasn't. I was confused and asked had her date changed and she said no. I'll be 34 weeks on Wednesday and I know that would make me 8 1/2 months. She disagreed and it's cool, it's not that serious. It bothers me when some women don't realize your really pregnant for 10 months. Oh well.