I had 2 swollen nodes in groin area after i strained my groin and was worried it was from cancer but the nodes have gone down now. is that good sign?

It is always a good: sign that something that was previously inflamed and swollen has improved spontaneously, aka without active treatment. However "straining" your groin would not be a usual cause for swollen lymph nodes-- the swelling could have been due to inflamed muscle fibers or inguinal ligaments... Monitor the situation closely but if things have improved, I would not be too worried. Thanks.