I Was Pregnant 4-5 Weeks When I Stated Bleeding And

I was pregnant 4-5 weeks when I stated bleeding and passing clots.. I went to hospital and they told me that my hormone levels went down, assuming that I had a miscarriage. I went home and for the past week I was doing home pregnancy test and all were positive. Until exactly eight days later that my test showed negative. Now I don't know if I'm pregnant or not.. I took the first dose of mifeprex 200mg.. what's going to happen if I'm not pregnant .. will I have effects in my body?
What if I don't take the next pill.. ?