I need advice..

So all this week I've been feeling a little off. I'm exhausted even when doing nothing or things that would never make me feel so tired, I am almost always extremely nauseous and sometimes even vomit, I'm bloated and my boobs are killing me! Now I know this sounds a lot like a pregnancy but my boyfriend and I have never had sex without a condom and im on birth control. I'm not perfect about taking it but it's not like I'm constantly missing or taking them late. I'm 7 days away from my period but today I noticed a brown discharge when going to the bathroom. Can anyone give me some insight because I dont know what this means. I know birth control isn't 100% effective and if I am pregnant I'm ok with it. it's just driving me crazy that I dont know what's going on with my body..