Strange bleeding and leg weakness cramps....

I started AF Saturday, I guess. I had dark thick blood and by that night it was just spotting. Sunday it was just spotting here and there. Today nothing but a backache, leg aches, leg weakness, extremely gassy amd fatigued. I test Friday bc I was 6 days late and got a BFN. I did take Clomid last cycle if that is the source. Any ideas????