Could I be pregnant already???

Guadalupe

Hi ladies I had a miscarriage in July. Had no d&c or anything like that. Everything just happened naturally and within that week. I had the miscarriage on July 17th on a Wednesday and my period came that Saturday. I had lots of unprotected sex after I stopped bleeding not to mention I was ovulating. Today I woke up super nauseous and sick. Could I be pregnant already so soon!?!?! According to the app, My period should be here this coming Saturday. Anyone had the same thing happen and became pregnant after a miscarriage????