I got my IUD 1/13/16 and the insertion was definitely painful, but I didn't go in on my period (it ended 1/11/16) and apparentally my uterus has a curve or something that made it for difficult to position. I had some cramps a few days afterwards but nothing terrible. Then recently this week, I've been getting HORRIBLE cramps that come in waves, but only at night. They never last for long, except for last night. It felt like something was being ripped out of me and I kept waking up every half hour in pain. Then this morning the cramps are back to vrry mild, more like a pressure than pain, and I had some rusty colored blood on my panty liner and in the toilet. Is this my period? The last few months my periods have been coming in the early days of each month (4th, 6th, etc) but mine have always flucuated.