From what I've heard from others is that many of us have different insulin needs at different times of the month, but the way our cycle affects our needs varies a lot from person to person.
For me, I used to need way less insulin from a day or two before my period until a day or two in. (Which worked as a useful but annoying reminder to put some tampons in my pocket.
)
Others are the opposite and find their insulin is like water at the start of their period.
I also often have a week where I need much more insulin than usual, but never found the discipline to track how many days after my period this happened to see if there was a pattern.
And now it's no use anymore, I'm 46 and I think my periods and the effect on my BG is much less predictable.
So like with all things diabetes, you likely have to find your own pattern.
The way I deal with those sudden changes in insulin needs is to adjust all my doses/ratios as soon as I see a sudden increase/decrease in BG.
I did ask my team a couple of years ago if using contraception could be of help with those swings but they had no idea.