Single thumbnail-sized blood clot + lower back pain

knottied75bc80b7233a6c9

Hi all - so I’m supposed to be almost 7 weeks pregnant. I’ve been feeling okay other than some nausea. Today I had weird cramping and lower back pain. A few hours later I went to the bathroom and there was a single blood clot (like a reddish brown) and now some very light spotting when I wipe but my lower back pain is gone. I am freaking out since I can’t get to the doctor for another 2 weeks. 

Has any one had this before? Is this a sign of miscarriage? Ectopic pregnancy?