I wonder if it's possible I got pregnant?

Good afternoon I would like to know if it is possible for me to have gotten pregnant, my last period was 11/01/2012 and my cycle is usually 27 days, I maintained relations on days 17, 20, 24 and 25 and I want to get pregnant very much, I did some simulations on the internet to know my fertile period but I'm kind of confused. Thankful!