What does it mean when your pelvis begins to hurt during pregnancy ?

Pregnancy changes: As the uterus enlarges with progressing pregnancy, the person may experience a variety of "aches and pains" in the pelvic region. The majority of these forms of discomfort are normal. Your obstetrician should be able to examine and reassure you.

Many reasons: It depends on how far along you are in your pregnancy. Pelvic pain could be due to a variety of different reasons (infection, preterm contractions, round ligament pain, etc.). Any significant type of pain during pregnancy should warrant an assessment by your physician.

Getting ready!: During pregnancy your placenta releases a hormone called Relaxin that softens your connective cartilage; this will allow your pelvis to open during childbirth but can also lead to pain/hip instability/pubic symphyseal separation, which can be painful. Exercising your stabilizer muscles can help; you may also consider buying a pelvic girdle/belly band for compression/support.