Ovulation after miscarriage

I had a miscarriage on Saturday 03/12/16 at almost 7 weeks, I went for a u/s on Monday and ofc as we thought i miscarried naturally and there was nothing left.
I healed emotionally as soon as I got home and I was already motivated to try again even before my next period as I was told wasn't necessary to wait.
The bleeding is getting less and less by the day and I have tried to do a pregnancy test to check the level of hormones has reduced and the lines was faint. I really want to try right away again but I am afraid I won't be able to detect ovulation as I did in the past with bbt and opk stick. Anyone have some good advice I can follow or would like to share their story? 
Thank you for reading this !