Stress, illness, anxiety, change of climate, big life change, extreme excitement or lots of travelling could be the cause. If you go to the doctor, they can give you a pregnancy test for free and it is more reliable
Do you have to take a smear test if you dont want to?
The purpose of a pap smear is to detect pre-cancerous cells. Cervical cancer is caused by human papillomavirus (HPV). HPV is transmitted by sexual contact. If you have never had sex, then you don't need a pap smear. If you have had sex, then you need to get pap smears annually until approximately age 60. If by the age of 60 you have been getting regular pap smears, and have never had an abnormal pap smear, then the frequency can be decreased (at the discretion of your physician).
The patient is the boss of her own health care (unless she's a minor, in which case the parent or guardian is the boss). Thus, you have the option of not getting a pap smear. You do need to understand, however, that if you have been sexually active, you could have contracted the virus that causes cervical cancer without knowing it. Without regular pap smears, you could develop cervical cancer without ever discovering it, and die.
When precancerous cells are discovered on the cervix during a pap smear, the doctor can fix the problem to make those precancerous cells go away.