Go to the dr. ASAP! I just went thru this! I had my miscarriage and had normal periods also...just like you!! But, I kept testing positive w/ a blood test by the doctors and it turns out I needed a D&C because some of the tissue and placenta was still in my uterus!! My HCG levels stayed around the 45 point mark and they did an ultrasound on me and noticed the tissue!! Get checked out because if you need to have something done, do it quickly or it could cause problems!! Hope I helped!!
And when I say I just went thru this...I mean, I literally just had the D&C done yesterday!!! So I do know what you are going thru!! Get checked out...it's better to be safe now than sorry later!!!!