Talk to Gynecologist on QUERY REGARDING COMPLETION OF PREGANCY TERMINATION

I had surgical abortion via uterine aspiration of 40 day pregnancy. And repeated ultrasound after 6 days to check/confirm the absence of any embryo and ultrasound was normal. Beta hcg test was also 147 at that time after abortion.I had bleed for few days and then bleed stopped and all my symptoms of pregnancy subsided like breast tenderness. Now it's been 4 weeks since that I am starting having abdmonial cramps again and mild breast tenderness. but periods are not still there.Do I need to repeat the ultrasound?? is there chance that process was not successful?