Low Hcg levels

keep

HCG beta level ( 21 dpo) :27.5

2 nd beta level ( 22 dpo ) : 48

3nd beta level ( 23 Dpo ) :73

4 th beta level ( 24 dpo) : 143

5 the beta level ( 25 dpo ) : 236

6 beta level ( 29 dpo ) : 726

Please guys share your experience . Last beta level didnt get double and my beta level is very low . Is there any success story with this kind of beta levels?