Ovulating after a miscarriage

I was just wondering if it was possible to ovulate before hcg drops to zero after a miscarriage and I was also wondering how long it can take for levels to go down? I had a natural miscarriage at 9 weeks, 2 weeks ago and stopped bleeding 1 week ago (baby stopped developing around 5-6 weeks) but I am still getting a pretty strong positive on hpt... And today I also have been having my usual signs of ovulation (watery cm and side specific sharp cramps)... Any advice helps! Also, how long should I wait before calling the doc about my hcg levels? They don't have me scheduled to come back until the beginning of march.