My Left Labia Majora Is Extremley Swollen And Kind Of

My left labia majora is extremley swollen and kind of hurts. i'll admit I might have been poking and proding at it all day to understand what it was. At first I thought it was just a bruise from the intercourse I had a few days back but now it really hurts and it's twice the size of my right labia majora. Is there anything I can do to reduce the swelling? My period just started as well could it be a result of that?