3 days late on mini pill

 I am a good three going on four days late. I have been on the mini pill Errin for three month and was just switched to Jencycla four days ago. Last month was the first time me and my bf only relied on my birth control pill as prevention. I have felt sick the past two days, heartburn, sore breasts, and headaches. Also some very mild cramping. I've taken two tests both have been negative.  Any pregnancies on a mini pill? Tips and advice on when to test what to be looking for? No signs of AF