I can't tell you if you are having a miscarriage. One of two things will happen: either this is something you are okay sitting with, or you can call your doctor, explain your concern and ask for an ultrasound. I've found the midwives and OB/GYNs I've worked with fairly sympathetic to this sort of need, and if they can't accommodate you at their facility, they'll refer you to an ultrasound tech.
I'm just telling you this because I wish I had known this earlier in my life. Some women do have light cramping and spotting and are fine; others do result in miscarriage. It's important to get checked out by a doc (in my opinion) because they can give you accurate information to allieviate your stress and uncertaintly, and they can help either monitor the continuation of the pregnancy, or give some pain relief and guidance if it is a miscarriage. There are some health considerations in this case, for continued reproductive health, and they will want to check in with you. I found that the resources and counsel offered at the time didn't necessarily feel helpful in the moment, but it was.
I'm hoping the best for you.