Hi everyone! Pregnant ladies... My period was 8 days late. A test show…

Hi everyone! Pregnant ladies... My period was 8 days late. A test showed two lines, but the second was hard to see. I took tests for two days; on the second day the second line was already a bit darker than the first time. In the evening of the 15th I had brown discharge, and on the 17th my period started. I took a test this morning — it looked the same as the first time: it showed lines but the second was faint. I bought a more sensitive, more expensive test; it also showed two lines, but the second was very faint. What’s happening? Has anyone experienced this? My belly hurt a lot during the day; it’s never hurt like this during my period... What do you suggest? This is my first pregnancy.