What Are The Side Effects Of Drop In HCG Level During Pregnancy?

I went to doctor after finding out I was pregnant and according to my LMP, I should be about 8 weeks pregnant. doctor did an ultrasound and saw a gestational sac which was shaped perfectly, yolk sac and bleeding around yolk sac but no fetal pole or fetus. I have already had 2 miscarriages so she thought it would be another repeat or shall I say another "blighted ovum". I was then refered to an imaging diagnostic place the following week after having my hcg levels checked twice and seeing that it has dropped in two days.....to our suprise the following week at the diagnostic place, there was a fetal pole and a heartbeat but she said it was very faint...My question is, can I still have a healthy pregnancy after hcg level dropping but detecting a fetal pole and heartbeat