Any ideas?

Okay ladies. I'm on CD33. I never go past 30 a day cycle seeing as how that is my average & it's usually right on. I ovulated on April 5/6 so CD 17/18 so I know I'm only 15/14 DPO. I took a test on 9/8 DPO got a negative, 11/10 DPO got a negative & then yesterday at 14/13 DPO got a negative again. No sign of AF. If I was pregnant based on my last period I would be roughly 4 weeks 4 days pregnant. So it still could be too early to show on a test right? With my son I found out at 5 weeks 1 day. Anyways? Happened to anyone else & still been pregnant?