How long does your period have to be irregular for a doctor to take you seriously? The last 4…

How long does your period have to be irregular for a doctor to take you seriously? The last 4 periods ive had were all one to two weeks late, one three weeks late, and im having bleeding in between them too. Im not on any birth control, i got the depo shot when my daughter was born but only the one dose. I dont know what to do. We're thinking about ttc once violets at least a year old, but im not even sure im ovulating since i bleed when im supposed to be in my fertile window. My periods are also much heavier and painful now too. Theyre the same length as they were before i got pregnant with Violet, but theyre much heavier.