Ive had unprotected sex. I've felt somewhat nauseas, tired, and constipated. I also feel pressure in my lower abdomin. I'm also been having headaches. It's been 7 weeks since my last period and that period was 2 weeks late. I got off of birth control back in june/july. Not sure if I could be pregnant or if it could be from getting off of my birth control? please help!