2 days late

My period is now two days late and I’m nervous to test.. I’m only 18 years old and I turn 19 next month. I’ve been nauseous for about two weeks now and it never goes away. I’m so exhausted I took a nap yesterday (I never take naps.. NEVER.) and went right to sleep at bed time which normally I have troubles sleeping. I have a lot of white lotion like discharge and it’s pretty heavy. No blood. I took a test about 5 days ago and it was negative but I just feel pregnant. I just looked in the mirror and my nipples were darker and really sore when i touched them. Yesterday i woke up in pain because of cramps and back pain and almost threw up, then I went to Walmart and it struck me again and had to run to the bathroom. I’m scared and don’t know what to do.. someone please help me. Does it sound like I’m pregnant? When should I test again?