Postinor 2 and Bleeding: Understanding Post-Pill Bleeding & What to Do

Question
Hello.

My last periods were on 21 September - 25 september and 19 October to 23 October respectively.
On the 2nd Nov was my ovulation day so I decided to stay safe and have sex on the 9th of November. As for protection, I took postinor 2. By 15th Nov, I bled I assume its just the symptom of the pill. The color of the blood was black at first then it slowly bleed and stop and bleed again. With that, I bleed till 20th Nov.
On the 23th Nov, I had sex again using Postinor 2.
However today, on the 30th, I noticed I have been experiencing slight bleeding and backache. Would this be my actual period ?

Answer
It is difficulty to assess that.  The Postinor changes the cycle.  You should consider a reliable form of contraception  This information may be of assistance.
http://contraceptive.ippf.org/search?search.searchtext=&search.ctype=Combined+Pi