Spotting whilst on pill

Ilona
Hey ladies,
I've been on the pill for over two years now (Levlen but just changed to Valette) and for the last 4 months or so have been getting spotting around mid- late cycle. Dr prescribed ralovera (progesterone) to stop the spotting and changed my pill brand but no luck so far. 
Anyone else have dramas with this? Or any recommendations?
Thanks 💕