How Long Does Dislocation In Knee Take To Heal?

Hi, I dislocated my knee 4 weeks ago when I twisted my left leg inwards whilst palying football. Ambulance staff got me to stand up and knee went back in its place.Was taken to hospital and Xray was all clear and had no broken bones. Gp had a look and advised to rest. have not referred for physiotherapy or MRI scan. Still can not put any wait on the knee but am able to move the knee up and down and can bend the leg around 90 degrees. does it worth going for MRI scan and is this normal healing time..