hcg levels

My first HCG level was 130 at 5 weeks 6 days. So 48 hours later it only jumped up to 330. the nurse said it was good because it doubled but should it still be higher then that at 6 weeks? I go for my first appt next Thursday and I took another pregnancy test yesterday that came back very positive. I'm just worried because I still don't feel pregnant and we had to use fertility treatments for our daughter and this one was an all natural surprise. Please help soothe my fears!