Post D&C results help!

Emma • 🌈👶🏼🤰🏼💙
25.02.17 no heart beat at 10 weeks
07.03.17 d&c
15.03.17 blood test for infection and check hcg levels 
21.03.17 ultrasound of pelvis 
Hey ladies I was looking for some advise after seeing my doctor (definitely changing for the next time and going private) today.
I went to get my results from my bloods and ultra scan and he said my bloods were fine no infection and my hcg level was 900. This was a week ago... does anyone know how long it takes (if not already) for this to return to 0? 
He said my ultrasound showed that the d&c was successful and nothing had been missed or left.
BUT
My report reads the following 
"There is a moderate amount of free fluid demonstrated within the right adnexa more the expected physiological. This could be related to recent birthing. This could be followed up in 2-3 months if felt clinically appropriate"
I said to my doctor I never lost my baby naturally and had NO natural signs of loss so had to have a d&c. He said maybe I had a cyst that popped (very blasé about it)
I asked if this could of caused my miscarriage if it was there before and he said  ahhh maybe not. (My blood boiling at how unhelpful he was being and giving me no answers) I asked do I need to be worried and he said only if you get pain. I explained I have pain but I don't know if that's normal from my d&c? To which he didn't say anything. I said can I try again after the 2 recommended cycles or will this cause another miscarriage and how will I know it's all gone? He just said don't worry take your folic acid and dismissed me.
Has anyone else had this? I've had a bad week this week so feeling very down and wanted to have the doctor say my body was back to normal and everything was ok to have some sort of closure on the worst month of my life. Especially as another woman at work announced her pregnancy and is due the week I was. 
Any advice or guidance would be great now as I don't know whether I'm feeling emotional and over worrying and this is all normal or that I have a shit doctor
Thanks for taking time to read my long post! ❤