There is definitely some amount of trauma that you have experienced that was followed by your periods.
I suggest you to get an ultrasound
of the pelvis done to rule out any damage to the pelvic organs.
For the time being, you may take Meftal spas
or other mild analgesics to get relief from the cramps and pain.
will take some time to go away, and do not worry about the greenish colour; it is how a bruise heals normally.
I wish you speedy recovery.