Iv been having unprotected sex, my periods arnt always exactly on time but they are usually around the same time no later than a week late. I was due on on the 26th of march, I didn't come on but I had about 5 days of spotting every now and again, I didn't even have to use a tampon/pad it was that light. I only saw light pinky/browny colours when I had wiped (not every time I went to the toilet), I'm not spotting now and it's 3 weeks since I was due on, I took a test earlier in the week and one day before yesterday and one today, they was all neg! I haven't had any stomach pains I usually get when im due and on my period. I have had slight lower back ache sometimes which I usually get when I'm on my period and due on. Could I be pregnant? Someone please help*