Need Help! Is this possible??

Let me know your thoughts, I tested and realize my sample

was very concentrated, the test showed no signs of positive, so I decided to dilute the sample a bit and it came out positive, anyone experience this and turned out pregnant? I plan to retest and go to the doctor on Monday. But I had a very late and heavy monthly cycle the 1st of this month, unusually heavy, but lasted 3 days as the usual. Just having symptoms of nausea and headache, low appetite, emotional. Your feedback is so greatly appreciated!!