ACL reconstruction - graft rupture???

I recently had my ACL repaired (about 2 weeks ago).  I went to Therapy last night and was doing a knee bending  exercise (bending off a 4" board), I heard a small pop and did get some pain.   I was able to do some other exercises to finish up the hr with the therapist such as leg shifts and side to side movements.  The knee hurt quite a bit and it did swell a little bit over night (and is still a little swollen today and more pain than usual).  The therapist did check the knee at the end of the session and said everything feels fine (did this by pulling on the lower leg in a bend position).  I do find that I have pain in the outside of the knee - under the knee cap.  I'm worried that I ruptured the graft - the therapist said this is hard to do without a fall or some type of trauma.   How difficult is it to rupture the graft?  Should I be worried and go in to see the dr?  I can bend the knee and walk on it (with some pain).  I was doing rather well with recovery and now worried that I have a major setback - I would be grateful for  any help or reassurance.

[Cik]

You MUST not go back to the operating surgeon but get a second independent opinion.  Anything is possible, including graft dislodgement.  Who was the original operating surgeon?