Ovulation & contraction type pains

So I got my IUD on Sept. 3rd and in the last 2-3 weeks I've gotten pains similar to ovulation pains and at times like contractions. I went to my GYN today and they did an ultrasound, my ovaries and IUD are perfect. Gyn checked me and said everything looked fine but she's prescribing birth control pills for 3 months on top of still leaving the IUD in (she said IUD is most likely not causing the pains since it's in the correct place)

Have any of you mommas had both pills and IUD before?? I've never heard of this.

Also she said my milk supply might dip.