Was I pregnant?

Hi I’m a little confused this month everything started to go wrong on my period. I started talking birth control pills and once’s I got my period at first everything seem normal but the 3 day I had very bad cramps and my whole body started hurting really bad so I took a pill for pain after that I went to the restroom. And something came out of me it was strange but I thought it was normal but as the days go on I’m scared to think I had a miscarriage. Can someone tell me how can I know if I did . I mean my period is already gone .