I have missed my period about 10 days .my cycle is regular and come on time.pregnancy test done is negative but i have diarrhoea.am i pregnant?

Pregnancy unlikely: Pregnancy tests are very accurate and not affected by foods, herbs, common illnesses, sexually transmitted diseases, vaginal spotting, or medications. A test gives a very reliable result 3 weeks after sex (3 weeks after when conception might have happened) or 1 week after missing a period. If done sooner, a negative result may be due to testing too early, such as less than 2 weeks after sex.