How will i know if my birth control pills have given me an enlarged uterus? i'm worried i'm pregnant

Uterine enlargement : Birth control has not been shown to enlarge your uterus, it fact it's a common treatment for heavy periods, sometimes caused by having an enlarged uterus from either fibroids, adenomyosis, etc. I'd consider a home pregnancy test if there is concern regarding pregnancy, as birth control is certainly not completely effective.