Help?!!

I only found out I was pregnant this Tuesday just gone with the first day of my last period being the 02/11/15, so should be roughly 6 weeks. I had some light spotting on Friday AM of dark dark red/brown which doctor said was nothing to worry about. Today however I've had a funny feeling in my cervix/uterus area...a tugging sensation/desperation for a wee/a stitch-like feeling. Anyone else had this?! Don't know whether to worry or not. It's not severe, as in I'm not doubled over in pain, but it's just uncomfortable.