Get thy self to a gynecologist. A creamy vaginal discharge could also mean an infection, especially if it has an unusual and/or unpleasant smell to it. Light headed could be early symptom of nausea. Urinating frequently usually doesn't come until later in the pregnancy. You shouldn't be having cramps, unless you are a lot further along that your originally thought. I watched a tv show where the woman went into the hospital, and gave birth. She didn't even know she was pregnant. It is possible.
As for finding out if you are pregnant or not, there are many different over the counter applications you can use. They will tell you within minutes, and are very accurate. I have had three pregnancies in my life time, and none of the over the counter pregnancy tests gave me a false positive. That was a long time ago. I would imagine they would have greatly improved them since then.
If you go to the gynecologist and haven't had a pregnancy test, tell them you think you might be pregnant and what is occurring when you go to set up the appointment.
If the pregnancy test comes up positive, call your doctor. Your doctor should be able to recommend a good OBGYN. Tell your OBGYN about your creamy vaginal discharge.