Implantation Bleeding?

So I'm on what I think is CD 12. Yesterday there was a TINY bit of pink when I wiped and today I had some drops of brown blood when I went to pee....hoping it's implantation because my periods are heavy right from the start. Period is due in a couple days. pregnancy test showed negative when I tested a couple days ago, but I want to wait until after AF is due to test again. Anyone had this and ended up pregnant??