Lower back pain + spotting + cramping

This is our third pregnancy in a little under 10 months. We've miscarried twice. After one cycle following most recent loss, we had a third positive test. I am now 5w 5d. I started spotting today, mild cramping, and pretty severe lower back pain (for days). Doctor's appointment is tomorrow morning. Has anyone else experienced this? And has it turned out well? I don't know how to handle three losses in one calendar year. Hugs and health to you all. Feedback is appreciated.