Help.

So Im about 2 weeks away from my period starting (Im on birth control so it’s extremely regular) and I haven’t missed a pill in over a month. Last night I noticed a good amount of brown discharge and it’s still happening today. About a week and a half ago I quickened up my period by 3 days by taking 2 then 1 pill in a day and a half then had sex the next day. We only use the pull out method. Should I get a pregnancy test? I’ve also had some soreness where my abs feel tight like I’ve been doing crunches but I haven’t. Also really tired.