Anybody else have this problem?

OK so the last 5 months maybe I've been having short cycles. 27 day cycle was the longest. My "my days" app AMD "glow" both say my cycle was due yesterday & still nothing. I am currently on cd29. I took a clear blue digital with the weeks estimator last night around 6:30pm & it said "not pregnant" however I am wondering if the test was faulty. I peed into a cup and almost right after I dipped the test in the waiting symbol started blinking so I pulled it out right away but I didn't leave it in there even close to 20 seconds. All of a sudden all the responses started flashing and then 3 mins later not pregnant popped up and stayed. I don't really feel AF Coming on but I don't want to get my hopes up either. Do u think its possible the test could be wrong?! TIA :)