Pregnancy chances after the age of 45

Sue
I'm 46 and starting menopause. Just starting. Like the beginning of her flashes. Lol. What are the risks of becoming pregnant after the age of 45 ? I have been taken off the pill due to it making my periods WORSE .. When I was started on the pill again  it was to stop having my periods due to the severe cramping while on my period ..  What  are the chances of accidentally becoming pregnant at 46?