Brown discharge weeks after Lletz

Hi, 

I just wonder if anyone had similar...not sure its worth ringin a gp for this. I had LLetz surgery under general anaesthasia ( messed up my back for some reason but another topic) . Everything went fine, had it end of October, by December everything was back to normal. No periods as im on Cerazette. 

So now in january, couple nights ago i had some strong cramps...like some.proper strong ones and since then i have very dark brown, old blood discharge. Its not strong, its only there when i wipe...but wonder if its something to do with the surgery still? Am i spotting? Never had it like that before. Shall i call gp? Wait for my next test in few months.time?