Period after miscarriage

Hi, I just miscarried at 5week +4 last Saturday. (1st pregnancy)
I started cramping and bleeding (passing clots) on Saturday, 
went to ER on Sunday and nothing seen on the ultra sound and my hcg levels were at 25. 
Went to my OB GYN the following day (Monday) and was told most likely a miscarriage and to re-test my hcg in two days. 
I did and my levels are now at 6 and the bleeding has become minimal (bled like a normal period with clots for 4days). 
My doctor wants me to test my hcg levels again next week as he wants to make sure they go down to zero. 
I really want to start trying again but was advise to wait for my next period.
I am very sad as I was very excited about this pregnancy but I am trying to stay positive and continue trying. 
I am just very anxious and the wait till my next period seems forever. 
Can anyone share how long it took for their period to come after the hcg levels hit a very low level?
Thank you!