IVF transfer and hcg levels slow raise

Patient: I had an IVF transfer on 31st july, 2015 and on 14th August had my first beta hcg test and it came out 8.4 and again on 17th August , had second test and it came to be 45. Doctor said, it is negative and asked me to stop all the medicine and wait for the next cycle. What to do now? Is it really a negative cycle or will there be any chances?? Please help, we are really upset and disappointed.

Symptoms: Constipation and no other symptoms