There are 4 basic pelvic shapes that are recognized by OB / GYNs. Unfortunately, there is no such thing as an "oddly shaped" pelvis. I think your doctor
was just using this generic term to say that you have a pelvic shape that is more unusual than the norm. The four different types of pelvic shapes are called 1. Gynecoid, 2. Platypoid, 3. Anthropoid, 4. Android.
The most common of those aforementioned pelvis shapes is the Gynecoid shape. This is a wide oval shaped pelvis that is ideal for have a baby vaginally. The other three pelvis shapes have some limitation in that they baby's presentation must be in a certain direction for everything to workout ideally. The Android pelvis shape can be difficult with larger babies especially in women who are diabetic. None of these shapes absolutely require c-section. The risks of a non-ideal pelvis shape is a prolonged labor which can (in certain instances) be harmful to the baby.
I suggest that you schedule an appointment with your OB / GYN. She can go into more detail about what she meant by oddly shaped. Depending on the shape of your pelvis, you may have a more difficult, though not impossible time having a vaginal delivery. Good luck.