Bleeding after a month - WHY?



I stopped bleeding/had my period at the same time after 3.5 weeks of LLETZ (my second one). Then, I had sex and bleed the day after (not right after sex). It stopped by the end of the day and hadn't done any excersise since. Now, 5.5 weeks after, it has happened again after some excersise and very steady sex. 


As I stopped having the pill and have polycystic ovary syndrome, I'm not too sure if it could be period-related.


If you bleed because it hasn't healed yet, does it happen right after? or also not until the next day?


I'm a bit scared because I stil have CIN2 after the LLETZ (according to smear test), but they couldn't see it on the biopsy, so I wonder if the bleeding could be because of something worse (because I read it's a symptom of CC). 


Can anyone throw some light here?


Many thanks