weird watery discharge?

so since ive gotten my mirena i have 2 week periods and i always get this watery discharge the day before i start but i just got it this morning and my period was over yesterday. does anyone have similar discharge or know what it is? i tried to look it up and it basically said it was nothing but its like a lot and its not colored, smelly or there when i wipe? and i have boric acid suppositorys and probiotics i can take if i need to.