I had unprotected sex with my boyfriend about 2 weeks ago we are trying for a baby, i am not due for my period until the 27th of this month but had period like cramps a week early, i thought i came on my period but it was very light had brownish colour and very light red colour and lasted for 3 days, now i feel like my tummy is stretching and has twinges feeling and itchy, my lower back is hurting, mild headaches , sort of like needles in my boobs and are itchy, my legs feel crampy, i have been sick a few times and still have some nausea , and a runny nose in the evenings, am i pregnant please help.