So i dont have unprotected sex, i always use protection. for the past few periods they have been lighter, almost brown, and i was supposed to get mine this past weekend. but ive been on the iud since early february and since like july my periods have been lighter and this months one is late. i had pre period symptoms (tender breasts, shed fertile looking mucus) around the time i was supposed to though. just no period. IUDs have been known to make periods lighter or even stop? is this normal? should i be worried?