Shocked.

I am so shocked.

I had a miscarriage around 4-5 weeks beginning Novemeber 29th. Bleeding stopped at the latest like December 3rd or so. He came inside of me once around that week and I tested on December 24th and to my surprise.. POSITIVE? I am now currently almost 6 weeks pregnant. How is this possible? I miscarried, ovulated and got a positive test all within 3 1/2 weeks?? Like what????