How To Strengthen Uterus?

Hi Dr, I am 26 year old girl . I m married for 9 months now. how can i check whether my uterus is strong enough to get pregnant because my in-laws already worried and forcing me to apply some kind of creams and ask me to eat weird foods so that i can get pregnant and they are saying i didnt get pregnant because my uterus is not strong enough to have a baby.