Injectable contraceptive

Mi sino po sainyo sane situation ko? First time mom po ako. Nagpainject po ako ng injectables contraceptives sa ika 3rd day ng period ko nung May 15. Then this month July 1, nagstart ako magka spot spot then July 5 until now July 11, may period ako pero light lang. Normal lang po ba ito sa naka injectable na contraceptive? Thank you.