menstural cup? light bleed

TMI SORRY FOR THE GROSS PICTURES. Okay just wondering why my period seems to get lighter every month. it also shortend by a day along with ore period spotting. my cramps are pretty bad. It's almost like my period is trying so hard to come but then can barely get anything out. this is after 11 hours. all the blood was brown old and lots of brown blood clots. any ideas why?