hi guys about one step ovulation tests

can anyone tell me how accurate or good are they ?? i know they are very cheap but i have spend load of money on clearblue they are too expensive so i really i'd appreciate any thoughts you have thx my period was on 18 june  2017  and i still have light brown discharge today so i have done a ovulation test with one step  and i can see a faint line ofc i know there is no lh surge yet lol i just had enough of spending a lot of money