Confused on period after miscarriage

So last Saturday I got a positive test then on Monday I began to have a miscarriage :( my period was Monday-Thursday. Friday just some brown spotting, yesterday in-between spotting and light. And then late last night and today it’s back to being red and bright. What is causing this? I feel like it start again after I had a bowl movement then had sex a few hours later. Is this normal? Usually my periods are about 4-6 days. But why did it start then stop then start again?