IUD Discharge

I've had the IUD for about 4 months, I had one in before but it got expelled! I got another one put back in and it stayed! I have noticed I'm constantly having discharge. Light and dark brown discharge. Never anything worrying like green, and spotting during my periods but I'm not worried about that. I just wanted to know if this constant discharge happens to anyone else? I really want my boyfriend to go down on me but I've been embarrassed because of the constant discharge! Opinions?