CONFUSED ? Could I be pregnant with twins maybe lost one?

Now I’m not so sure if I had a chemical or miscarriage I was bleeding and clotting for 4 days straight a lot of it with mensural like cramps and I thought I was having a miscarriage or a chemical since I was only 3 weeks pregnant but it just completely stopped no more bleeding I only cramped for 1 day now it’s like brown blood but only a few spots did I miscarry or have a chemical or could I still be pregnant?