Hi, I Saw My Menstrual Flow(4 Days) On The 18th

Hi, I saw my menstrual flow(4 days) on the 18th of July after using cytotec for an abortion on the 25th of may(d flow was for 9 days). On the 18th of August the flow came but lasted for a day after seven days I had a heavy flow which lasted a day. Went to the hospital and I was told am pregnant after having a urine test. The ultrasound scan said I was 5weeks and six days gone. I don't understand this. Can u please help out