So i missed my period for 2 months almost three. and then it suddenly came back the next morning after my partner and i had intercourse. except it didnt feel like a regular period. i didnt get cramps beforehand like i always do, actually i havent had any. and all it really is, is that it's extremely dark compared to what it usually is. and its only noticeable when i wipe. its not heavy and it doesn't have any particular unpleasant smell. whats happenning?