I would definitely keep testing, although I suppose it depends on what your cycle is like and when you normally ovulate.
For me, Im sos irregular that even after I get a positive I keep testing just in case, right up until my period shows. I am now 7dpo but still testing (Stark white). But I know Im probably an exception. If you know you usually O around this point in your cycle and think that was it, then maybe no point in continuing.