I had my last period on October 26 and it was very irregular (not like my normal periods at all). So I used a ovulation calender on the Internet to help my determine my next period because I'm trying to have a baby. One site said I was suppose to have it today and another says tomorrow. I am very confused because if the true date is today then nothing has happened yet. It felt like it wanted to come last week but nothing. So I was just wondering can you really trust what they say?