Cramping at 6wks

I'm 6 weeks pregnant, and today, like 10 minutes ago, I started having dull cramps in my lower back on my left side. Its not unbearable or anything and it came, lasted a minute and hasn't come back. Is this normal in early pregnancy? I'm also having dull cramps here and there in my uterus too, but I think that's more so my uterus stretching because they're less intense than period cramps, only last a few seconds and come mostly at night when I'm trying to go to bed.