Is it a miscarriage? Bleeding 4.5 weeks. TMI

Hi, I am freaking out. I had a dark brown discharge all day today.called a nurse and she said it could be irratated cervix because of sex a few days ago or something else... I assume she meant mc, but didn't want to freak me out. I was told to monitor it for now. Please tell me someone had something similar and everything was alright with the baby 😭