Help please

Af was nearly 3 weeks late. Had spotting on and off in those 3 weeks but no cramps or anything major. Last week i started what I presume was af. Usually when it starts i get major cramps week before and first 2 days of starting. I usually start of with little bit bleeding then gets heavier having 2-3days heavy some clots, then last 3 days spotting.this time no cramps It's just been a week now really heavy bleeding. Isn't showing any sign of slowing down. Has this happened to anyone else ? Does anyone have a clue what's happening ? I'm getting really fed up of constant bleeding now j just want it to be over so we can get back to ttc. Sorry if I've been ranting on.