CM changes

I ovulated around 2/19 (I had my usual ovary pains that day) so I’m about 13 dpo. I usually have watery CM until the day of AF. Today when I wiped I noticed a snot like consistency that was tinged yellow/brown slightly. It was a small amount. I’ve had some lower abdominal cramps/discomfort, very sore breast/nipples, very nauseous, moody, lower back pain and fatigue, half I get with AF half I don’t. I had a negative test this AM. Is this just normal changes or maybe an early sign of pregnancy?