Am I having a miscarriage?

I am 4 weeks and 3 days pregnant and last night I started having some very light brown discharge and this morning I woke up with quite a bit of red bleeding and some cramps. Has this ever happened to anyone and everything was still okay? I am so scared and heartbroken that I'm losing my baby. I am waiting for a call back from a nurse at a clinic where I haven't even been seen yet. I am high risk for ectopic pregnancy because I had a tubal reversal in 2015. I lost a baby in August of 2015 due to ectopic and I lost my right tube. Someone please tell me everything is going to be okay! I'm falling apart right now!!