My period is three weeks late, but I have irregular periods. Yet I had ovulation symptoms half way through my cycle so I thought I'd be on time this month. I've had thick brown spotting on and off for the past month when I usually only get it a week before my period. I had sex on dec 25th, 27th, and 31st and we used condoms. Besides the late period and spotting I haven't experienced any other symptoms, am I pregnant?