I have been on Tricira low 28 birth control for about 3 years, I have been having sex with my boyfriend for about 1 year and neither of us have had sex with anyone else. About 2 months ago I missed a whole month of birth control because I ran out and couldn't see my doctor. I got this brownish red discharge in my underwear and it lasted for a month or so. It went away for about a month but I just went to the washroom and I have it again. What is this from? Is it preventable? Should my boyfriend and I get checked?