How soon can you tell if you are going to have twins? I'm getting mixed answers from Google, but I know there are moms of multiples on here!

I had a very strong feeling I was pregnant before I found out, and got an unbelievable amount of signs that I was. Now I am pregnant and am seeing double, there are twins every.where. Shows about twins on TV, double stroller spam e-mails, a number 4 chizzled into the garage in our new house, I'm almost sure i'm going to have twins!