Could I be pregnant???

So I've been feeling sick to my stomach for about 3 weeks now. To the point I didn't want to get up and go to work. It happens right before bed around 8 or 9 and in the morning when I wake up at 5:30. After that I get very nauseous and almost throw up. I can feel it in my throat and it starts with some burping. It goes away a few hours later but then it happens again and this time I throw up a little in my hand. I'm usually not like this. To add on to this I've been having some cramping but sometimes a pulling or stretching from either sides of my ovaries. And constipation lately. I plan on going to planned parenthood today for a test but I'm nervous because usually when I'm pregnant the test are all negative. And I've been taking my birth control pillson time. I just stopped 2 days ago because I'm concerned. Has this happened to anyone else or any insight??