First time pregnant - low hcg and REALLY scared

Lina

Hi! My cycles range from 33-36 days- my last period was on 21 October and I ovulated on or about 12 November - I had a very very faint line on 25 november and had a blood test - hcg results were 7 - doctor said this probably means I'm not as far along as we think - So 5 weeks from last period and 2 weeks from ovulation- doctor has said to retest hcg in a few weeks but should be okay- nauseous and fatigue with sore breats. I keep peeing on a stick and line keeps getting darker. Thoughts?