6 weeks and 1 day, light pink spotting?

Ive never spotted in my past pregnancy and made it all the way up to this point without any spotting as well? Should I be worried? I slept on my stomach last night and had a really hard time falling and staying asleep. I was literally tossing and turning all night until I woke up today at 9. I have a dull lower backache.. So should I be concerned?