5-6weeks bleeding?

Hi new mummies, wanted to ask for some advise. I had bleeding with no pain for 3 days in week 4 (not heavy but pink-red)… doc put me on duphaston and bleeding stopped However i noticed if I stand up for more than 20 mins I’ll have bleeding again :( but if I lie down got no issue? Bleeding is not heavy and no pain at all, but will be dark red… anyone can advise what to do? Very troubling :(