Threatened miscarriage at week 5

Hi all, I have been having brown spotting before I knew I was pregnant (before missed my period). So I thought it could be implantation bleeding when I tested positive on pregnancy kit. But 2 days later, my brown spotting filled panty liner and next day bleed bright red that’s enough to cover almost 70% of medium pad. I went to KKH O&G and was given duphaston and cause I’m only at week 5, can only see the gestational sac. Today will be my 2nd day on duphaston, there is no bleeding or spotting in the morning but night time have brown spotting that filled 60% of panty liner. Is this normal? How long will the spotting be gone. Had a blighted ovum on Jan.. this will be my rainbow baby, so lost and scared as prev I have no bleeding or spotting :(