The copper iud can potentially make your period and cramps heavier/more painful, hormonal iuds can make your period stop altogether, but can also make your cramps more painful as you’re adjusting with the hormonal iud you can bleed very irregularly for the first few months (3-6) with the copper iud your period will come on your regular cycle but might also be a bit longer along with heavier lots of people get both iuds taken out before adjusting because they bleed a lot for a long time but don’t let that deter you from wanting one, both are going to hurt during the insertion BUT definitely talk to your doctor about possible pain management aside from just Tylenol or Advil, advocate for pain management and if the first doctor tells you it won’t hurt and to just take Tylenol or Advil, find another one who will