Prolonged periods- regesterone. Problem?

I have got my periods on Jan 19 to jan23 after which 6 days gap again I got bleeding so I went to hsptl they gave me medroxyprogesterone 5mg for 21 days...but it didn't stopped even after taking this tablet 10days so I again went to hospital they asked me to take a scan of abodomen..and ask to take blood test..and my results were in scan - no abnormality detected...in blood test also everything was normal then my gyne gave northeistrone norgest tablets for 21 days 5mg even after taking this tablet for one week also my bleeding was not stopped but it reduced...so again I went to my gyne she told me take 5mg morning and 5mg night this norgest tablet from feb21 and continue till March 4th now it had stopped but when I wipe my discharge it has some red strings or small thread like red strings and sometimes the discharge itself is yellow in colour and after stopping this she asked me to take regesterone 5mg for 21 days??is there any problem??? Why she suggested me to take regesterone tablet