Are you short of breath? Does your bladder seem to be the size of a thimble? When you get in bed at night, does your stomach acid sometimes end up in your throat? (Yuck.)
A lot of pregnancy symptoms can be blamed on hormonal changes, but a good number of them are also the direct result of having a baby take up all that room inside your body - room that used to belong to your lungs and stomach and digestive system.
The left-hand image shows a woman's body before she gets pregnant, and the right-hand image shows her body carrying a full-term fetus. See how squashed your bladder is? Look at the way your stomach pushes up against your lungs. Check out what's happening to your intestines! No wonder everything feels so crowded in there.
See larger images at the Childbirth Connection here (pre-pregnancy) and here (full-term), as well as diagrams showing what your body looks like during the weeks in between conception and birth.
What pregnancy symptoms are you experiencing?