What Causes Pain In Pelvic Region And Tiredness After Coming Off From Contraceptive Pills?

I have recently come off the pill and had my first real period 28th july. I have felt bit sickly. very tirednd now this morning feel a hevy sensation in my pelvic area. I think i would be due to come on on fri. I also have sensitive breasts. i did a test sat but was negative. do you think im pregnant