Hi, I'm 5 weeks pregnant and have been having low back pain. Also there is some cramping (mild and not constant) along with some twinges in my stomach. I have no spotting. Is this a sign of miscarriage?

The back pain is like what I would feel during PMS or if I slept on the couch. I'm so scared of miscarrying again, 2 years ago I miscarried at 19 weeks. If someone could shed some light on the situation I would appreciate it.