Should I be worried? Weird month?!

Usually my withdrawal bleed starts on day 4 and is heavy the first two days. This time it started on day 3 around 5pm but was lighter and a rusty color for 2 days. Now on day 3 of the withdrawal bleed it’s heavy and bright red? Cramps lasting a little longer too? I also had some brown spotting in the muddle of my pack. Is this just a weird month for me or is this normal forthe bleeds to vary?