My LMP was 6w2d had spotting go to ER u/s was done showed gest &yolk sc hCG level 2053, rep after 4 d was 2478 not doubled should I worried?

Yes it should have. Doubled, but I would get one more in 3 days should double in 3 days and they should have checked a Progesterone level, as a low one is not good and repeat the us in one week cause if u were 6 wk 2d, then in one week should see a htbeat in the sac, so see your obgyn, as an obgyn is better to follow u than.
Abnormal. The HCG rise you describe is abnormal. It is also atypical to see a yolk sac already with an HCG level of 2000, although it is possible. All this does not necessarily mean that your pregnancy is for sure abnormal, since different labs or a vanishing twin can cause an abnormal rise in the hcg. Simply follow up with an obstetrician or gynecologist to recheck the levels and perform an ultrasound.