im on the contraceptive pill called yasmin. Previously Ive been on yasminelle but changd to yasmin 3 months ago. So I ve taken 3 sets of yasmin. my period is due this thursday 28th June but on thursday 14th June (exactly 2 weeks after my last period and bang-smack right in the middle of my cycle when i think i ovulated) i had sex with a boy. We used condoms and were careful. i take my pills carefully every day and have not missed a pill. However, 2 nights after that thursday nights sex I was very sick with diorrhea and since then I ve suffered nausea every morning and night and even sometimes during the day. i also have lower back pain . I am very worried that I have fallen pregnant because my pill has not worked somehow. I am 27 years old, 6kg, 5ft tall. Is there a chance that I am pregnant??