PHMM Grade 3 tear in right knee. 3 tear.

I am a marathon runner and from last 6-7 months, I was having mild pain in right knee while bending. Last month, pain was aggravated during my run so I stopped running from that day and done MRI. There was grade 3 complex Posterior Horn Medial Meniscus Tear in my right knee. There was stiffness and pain for first 7-8 days. But things got better with the help of knee strengthening exercises and PT. Now my stiffness and pain almost disappeared, ROM is also very good. I am able to walk 7-8kms per day and squatting 30-40 count per day. I need your expert advise on whether I can start running again or should I wait for more time. Also please let me know if I can do MRI scan again to check as I believe there was misdiagnosis of Grade 3 tear.