when do you start feeling baxtion hicks

so I'm 30 weeks and my period would sometimes be a month to a month and two weeks apart I do not want my baby born in December. I'm curious when they start becuase the only pain I'm getting is my pelvis bone on the back mostly on my left butt cheek like as if I need to pop my back but I can't the pains like a 6ish 7. it's not that I don't think there's anything wrong with December I just really love fall and want her to be born in my favorite season.