I'm 25 dpo., about five and a half weeks. I had an ultrasound today which showed a yolk sac but they said it was too early to see the baby. They said the sac measured 5w2d. I'm probably overreacting but now I'm over thinking everything and I feel like my symptoms are not as strong as they were. I only had a few waves of nausea today and feel like there was more earlier in the week. I've had early, severe morning sickness with my other four so I feel like I should feel sick at this point. Back at 13 and 16 dpo I had hcg levels done, 13 dpo was 186 and 16 dpo was 679 - on the high side and doubling every 33 hours. The hcg wasn't redone, I wish I had asked. The ultrasound is going to be repeated in two weeks but I know I'll go nuts until then, can anyone offer reassurance that it's ok to have fluctuating symptoms and no baby on the ultrasound yet?