Due Date?

TRN87

I was wondering what you ladies think??

I was charting and using opk's while TTGP, but FF.com (and a lot of other sites as well) predicts my due date is June 12th, when I put that date in the bump ticker it says I am 4 weeks pregnant, how is that possible if I only ovulated 12 days ago?  Should I just go with the June 12th date or assume it's closer to June 26th?