is it normal for me to suddenly get a heavy period

so i’ve been taking birth control for i wanna day 2 1/2 years, at first it made them really regular and they weren’t usually that heavy, over time they got lighter and lighter and sometimes i don’t get them, they got so light that i had to buy a menstrual cup cause i couldn’t wear tampons and i was wasting lads. sometimes there would be like my uterus lining, brown blood, but very rarely new blood. today my cramps were really bad and there was a lot of blood in my cup, i haven’t had a period like this in maybe over a year. is it normal for them to get lighter and lighter and not get one, then suddenly have them heavy? the last time i had a heavy period was when i left my pills over a friends house and couldn’t get them but after my body adjusted back they’ve been very light since then and i haven’t missed any