If you feel lightheaded, especially when you get up from lying down, be extra careful. Dizzy spells are common, especially as your pregnancy progresses and you get bigger, since your heart has to work harder against the forces of gravity to get blood to the brain.
Try to stand up very gradually, in stages, from lying to sitting to standing. Dizziness can also occur if you have been standing for a long period of time, since blood may collect in your legs. Keep moving to encourage the blood to be pumped back to your heart.
Alternatively, you may feel dizzy due to low blood-sugar levels. Other symptoms of low blood sugar include feeling sweaty, shaky, and hungry. Even if you're feeling or being sick, try to eat little and often to ensure that your blood-sugar levels remain stable.
If you regularly feel dizzy, speak to your doctor, who will carry out some basic health checks.