What’s wrong with my cycles???

Some may consider my story TMI.. Normally my periods are very heavy for the first couple days and I have unbearable cramps, nausea and fatigue. My cycles have always been irregular, Where I don’t know when they will come and I’ve even skipped months. The last couple months I’ve been experiencing even unusual cycles. ..December 3 I started spotting and then went into a very light period that lasted a few days and went back to spotting with no PMS symptoms. End of December I spotted for about a week, but more of a brown discharge than red. Now, January 15-19 I began spotting/bleeding, a mix of brown discharge and some blood but it was very light to the point I didn’t need anything more than a panty liner, and again no PMS symptoms. Can anybody explain why this is, or if I should be concerned.