"well, i just got the mirena march 20, 2015. the insertion hurt so bad (i guess its because i have no kids). i&#039;m 18 and right afterwards i began to bleed. i bleed off and on for three days and now, march 26, i&#039;m having light bleeding. i came on my period three days ago and had terrible cramps. from the look of it though, i may be bleeding for 2-3 months. i just hopes it gets better! thank you all!"