Thick white vaginal discharge
may be due to some vaginitis
if associated with itching or burning; other wise it is seen in the pre-ovulatory phase of the menstrual cycle. It is possible to get early pregnancy
symptoms even as early as 3-4 weeks. You should wait for your period and take a pregnancy test 3-7 days later, if you miss it. Your symptoms can be premenstrual as well as due to early pregnancy. Take care.