Prolonged period with big clots

I didn’t have a period in March and then April onwards I was having light spotting the entire month. Last week of April I got a heavy period with really big clots which lasted about 20 days!! My doctor said it’s mostly PCOS and told me to get on the pill (Diane 35) for 21 days and then my next period would come within a week of stopping the pill. It did come but it’s back to being very heavy. I’m only on day 3 of the period but the size of the clots is worrying me! This is also the first time I went on the pill so not sure if this is how a period looks like once you stop the pill. Any help would be much appreciated!