Heavy Implantation Bleeding??

ok so here goes! About a week ago I got what I thought was my period, but It was about a week early. I bled pretty heavy for 2 days and then it lightened on the 3rd and 4th day. I took a test two days later and I could barely see anything. I tested two days later again and got a darker line, but still faint (picture attached). Has anyone experienced this?? Someone mentioned a chemical pregnancy but I researched this and that seems to usually happen after when you should get your period not before. Not sure though! I took the test because I felt like I had the flu, I was exhausted and things were starting to smell and taste funny. And my boobs hurt! Has anyone had heavy implantation bleeding and been fine? Has someone bled like this and had the lines on their test get darker, not lighter? Going to test again tomorrow but trying to not worry!

not to worry!