Sana ma advicesan nyo ako

Nanganak ako nung june, since then nag brebreast feeding ako. After a month wala pakong menstruation nag sex kami ng hubby ko. And then, nung 2nd week mg july nag karon nako non and then i decided to put IUD to control family planning. Ngayon worried ako kasi di pako nag kakaron 2nd week na, possible kaya na buntis ako? Pls help