My baby has 11 months now.

Yes. Unless you are breastfeeding.

Check out Billings or Fertility awareness techniques, and learn to read your ovulation from the state of your cervical mucus.

Yes. You ovulate before you get the period, so you could get pregnant. The first period after the birth of a baby is usually anovular (no real ovulation) but you wouldn't want to count on it, particularly at 11 months after birth.

Ever head of "Irish Twins"? That's two babies born in the same year because the mother got pregnant again so quickly.

Yes... remember that you will ovulate first. Some women are surprised to find themselves pregnant when they hadn't resumed periods yet. Obviously having your periods return generally means that you have resumed ovulating as well.

Are you or have you recently been breastfeeding? This can sometimes be enough to hold ovulation at bay, but again best to use protection if you don't want to become pregnant.

If you are wanting to become pregnant, you'll have to watch for other signs that ovulation has likely returned. If you are breastfeeding, it may be just a matter of once you wean a bit more cycles will return.