Nausea help

Nobody has responded to me in the other groups so I'm desperate now, I've had constant nausea when I wake up, when I eat, and just throughout the day. This happened last month too for 2 weeks straight, now it's been happening since friday. I take birth control and I've been taking it for almost a year now and this has never happened to me until last month. I don't hardly eat anymore because it makes me sick to my stomach, and I've had cramps in my uterus/ovary area, it gets so bad to where I double over in pain sometimes. I really need some help on what to do, the last time me and my boyfriend had sex was on the 12 and he came in me, I only have a week left of pills in my pack and last time I had my withdrawal bleed my symptoms stopped, please help, should I switch birth control?