you should not be concerned about what is occurring... its normal for your blood to darken as whats coming out as your period comes to an end is old blood....clots are normal most if not all females get them....and some girls get cramps that are mild others more severe .... heat compress works wonders and relax as much as possible more easily said then done of course. the inability to concentrate and mood swings are just your hormones it happens to the best of it... if its too much to bear speak to your obgyn and see if there is a birth control out there to help yield such frustrating symptoms XD