It is your port....Don't worry my doc says every time I go in to get a fill that my port will move as I loose weight. Everything moves as we shrink.... This is a good thing not bad. it is sore only cause it is hard and sewed into you muscle wall, if you hit it hard enough it will bruise, and it will hurt.
I think you will be fine, let your bruise heal and put some ice on it.
Thanks for the reminder to be careful.....