Replying to Could you help please, Im rather worried!

Well something VERY wierd has happend to my knee.
I had and ACL reconstruction nearly 2 months ago and have been working on the recovery on my knee dillagently. Ive been keenly watching the level of swelling and have been pleased with how its reducing.
I have neither twisted,sprained,over flexed,hyper extended,knocked or otherwise hurt my knee in any way.
But this afternoon it started to swell, i went as usual to the gym and did my cycling and excercises. and it got bigger.
Its now massive and the skin in taught with the amount of swelling.

Im in no pain what so ever.

Why is it doing this? can the newly grafted ligament undo itself??? would that cause the sudden swelling??

If anyone knows anyting i would really like to know. Its 12.43 and im going to my docs straight away 2 morrow but thats not gonna help me sleep tonight.

Cheers

Rich