Heavy bleeding with positive test

My period was a week and a half late with all negatives across the board. I started spotting 2 days ago and thought potentially implantation bleeding because it was extremely light and abnormal for me (I have endometriosis and typically start heavy and go for 4-6 days before it lightens up) so i took another test and got a faint but clear positive. Yesterday the bleeding got so heavy I was soaking a pad every 2 hours. Today I'm back to light bleeding and took a test this afternoon and it was a clear negative. I have to assume the worst, but does anyone have a happy ending with something similar?