Diagnosed with threatened abortion/miscarriage.

After bleeding yesterday I went to the doctor and they said it may be a threatened abortion. since I'm only 5 weeks they really can't tell me anything. The doctor really didn't know and she said it could be implantation bleeding. I had an ultrasound and the tech didn't notice anything out of the ordinary. My HCG levels are at 101 and the doctor told me that's normal for early pregnancy but the number doubles . I have to wait 48 hours to do blood work again. I'm still bleeding and cramping a little. The pain is not bad. I have had a miscarriage before at 7 weeks and the pain was excruciating and there was a lot of blood. I'm starting to loose hope but my husband tells me to keep thinking positive. has anyone else been diagnosed with threatened abortion but still had a successful pregnancy? or is just it too late?