please help!!!

Mary
I usually have 25-27 day cycles. I track my CM to tell when I ovulate, and that usually works fine and based on when I start my period it seems about right, ovulating between days 10-13 based on my cm. I tend to dry/get creamy around the 14th day of my cycle. Based on my tracking this month I feel like I O'd on around the 12th-13th cycle day. Which means AF is due any second. (27 cycle day today) I took a pregnancy test around 12-13dpo, 2 days ago, with a cheap Walmart brand test. It was negative. My question is, since I haven't gotten AF yet, do you all think I'm out, or would I have gotten my BFP by 12-13dpo.... or do I still have a chance. I'm grasping at straws, and want my positive so badly. But since I'm pretty sure on my ovulation date, I should of started my period by now. Any advice or input is appreciated!