Suffering With DUB, Normal USG, Pap Smears, Advised D&C And Hysteroscopy If Bleeding Continues. Precancerous Condition?

i am 38 years old with 1 child. i have dub for the first time dub is now since 3 weeks. (my periods were delayed by 20 days and then i got them on 1/7/2012 eversince i have dub. my usg is ok with endometrium lining of 6.9mm and rest in order. i have been put on primulut n for 2 weeks . though my bleeding was around 80 % to 85 % control it has not stopped completely. my doctor advises to stop primulut dose to get my next periods and if it behaves the same way to go for a d and c and hysteroscopy . my pap smears have been ok, sometimes bacterial/ fungal infection and at one of the times cervical mild dysplasia . kindly advise if i am looking into any precancerous cancerous conditions, and what is the advise