Help! Is this normal or should I be worried?

Lilly

I’m currently between 3-5 weeks. The doctor can’t confirm how far along I am because my hcg level is only 63 and it’s too early for an ultrasound. I’m having light cramps with light pink/brown discharge that comes and goes. There’s no blood clots or anything but I am RH negative. I have had a miscarriage before but this seems different. I don’t know if I need to be worried or not.