Increased 
vaginal discharge and food carvings can be labelled as symptoms of 
pregnancy, but pain in lower abdomen definitely not. 
The cardinal symptoms of pregnancy are:
1. Cessation of menstruation
2. Nausea and 
vomiting with food carvings
3. Frequency of Urination 
4. Breast Changes:
    * Brownish discolouration of Nipples and 
areola (Only during first pregnancy as this is irreversible change) and increase in the size of areola. 
    * Engorgement of breasts
    * Secretions from the nipples
    * Tenderness of breasts 
However, they have to be supported by an Obstetrician's clinical examination. 
For confirmation, 8-10 days after missing a period, pregnancy test on urine and/or 
Ultrasonography may be carried out. 
Only on a couple of symptoms, pregnancy is never diagnosed.