Spotting/bleeding at 6 weeks

Hi everyone, i had my urine test after one week i missed my period. And my upt showed positive. I considered myself pregnant on that time. I haven’t checked with doctor since it was too early. Then at my 6 weeks, I’m having cramp & spotting/bleeding. I thought it may be an early sign of miscarriage and dangerous to my pregnancy. When i check with doctor, their upt result was negative. My blood test hcg result was not clear and i need to do it again next week. My bleeding quite similar to period but it was only lasted for 3 days. I’m now worried and a bit sad because I’m hoping that I’m pregnant. Anyone facing this before? Mind to share your experience or opinions. Thank you ☺️