It should be "I have been practising these tenses for three weeks now. Do you think I have made any progress?" This sentence indicates that the speaker has been continuously practising the tenses for three weeks leading up to the present moment and is asking for feedback on their progress.
It should be "I have been practising these tenses for three weeks now. Do you think I have made any progress?" This sentence indicates that the speaker has been continuously practising the tenses for three weeks leading up to the present moment and is asking for feedback on their progress.