Should I be Concerned

Hey ladies, so my cycles are every 28 days and I usually bleed for 5 long days😩 but last month was different, I bled for two days and then it died down to brown spotting on the 27th-29th and I have no idea why. This has never happened before. I’ve suffered with bad backaches, the odd nauseous day, tiredness and ughhh non stop greasy hair no matter how many times I wash it a day.