Could it be the IUD?


I got a copper IUD at the beginning of February and that same day i had my period.... ive always been VERY irregular meaning i have my period one month yes one no... but now ive noticed a light brown discharge.... could it be the IUD? Also ive been kinda sexually active but we always use condoms plus IUD... sooo is my body still adjusting to the IUD? or is it pregnancy?

Need advice... thanks!