when to start pill

i’m 15, i’ve been prescribed the combined pill by my doctor for my bad acne, she said to start on the first day of my next period

but, my periods are SUPER irregular to the point my next one could be in 2 months?!

i want to start it now to get my skin better (and quicker) but my last period was over a month ago- i’ve heard stuff about heavy bleeding if you start “mid cycle”

is this true? i really cant cope with that

has anyone had any experiences of starting the pill midcycle? or stuff they were told? it would be massively appreciated xoxox